BlackRock Total Return Fund

Fund Overview

Key Facts About BlackRock Total Return Fund

Investment Objective

The investment objective of the BlackRock Total Return Fund (the “Fund”) is to realize a total return that exceeds that of the Bloomberg Barclays U.S. Aggregate Bond Index.

Fees and Expenses of the Fund

This table describes the fees and expenses that you may pay if you buy, hold and sell Class K Shares of the Fund. You may pay other fees, such as brokerage commissions and other fees to your financial professional or selected securities dealer, broker, investment adviser, service provider or industry professional (including BlackRock Advisors, LLC (“BlackRock”) and its affiliates) (each a “Financial Intermediary”), which are not reflected in the table and example below.

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)¹		Class K Shares
Management Fee^2,3		0.34%
Distribution and/or Service (12b-1) Fees		None
Other Expenses		0.03%
Acquired Fund Fees and Expenses⁴		0.01%
Total Annual Fund Operating Expenses⁴		0.38%
Fee Waivers and/or Expense Reimbursements^2,3		(0.01)%
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements^2,3		0.37%

¹	The fees and expenses shown in the table and the example that follows include both the expenses of the Fund and the Fund’s share of the allocated expenses of Master Total Return Portfolio (the “Master Portfolio”).
²	Based on the most recent fiscal year, BlackRock receives a management fee from the Master Portfolio for investment advisory and certain administrative services at the annual rate of 0.05% of the Master Portfolio’s average daily net assets, a portion of which is paid indirectly by the Fund, and receives a management fee from the Fund for investment advisory and certain administrative services at the annual rate of 0.29% of the Fund’s average daily net assets for an overall management fee rate paid by the Fund of 0.34%. In addition, as described in the “Management of the Fund” section of the Fund’s prospectus on page 33, BlackRock has contractually agreed to waive and/or reimburse fees or expenses in order to limit Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements (excluding Dividend Expense, Interest Expense, Acquired Fund Fees and Expenses and certain other Fund expenses) to 0.39% of average daily net assets through January 31, 2022. The contractual agreement may be terminated upon 90 days’ notice by a majority of the non-interested directors of BlackRock Bond Fund, Inc. (the “Corporation”) or by a vote of a majority of the outstanding voting securities of the Fund.
³	As described in the “Management of the Fund” section of the Fund’s prospectus beginning on page 33, with the exception of the Fund’s investment in the Master Portfolio, BlackRock has contractually agreed to waive the management fee of the Fund and the Master Portfolio with respect to any portion of the Fund’s or the Master Portfolio’s assets estimated to be attributable to investments in other equity and fixed-income mutual funds and exchange-traded funds (“ETFs”) managed by BlackRock or its affiliates that have a contractual management fee, through January 31, 2022. In addition, BlackRock has contractually agreed to waive its management fees by the amount of investment advisory fees the Fund or the Master Portfolio pays to BlackRock indirectly through its investment in money market funds managed by BlackRock or its affiliates, through January 31, 2022. The contractual agreements may be terminated upon 90 days’ notice by a majority of the non-interested directors of the Corporation or the Master Portfolio or by a vote of a majority of the outstanding voting securities of the Fund or the Master Portfolio.
⁴	Total Annual Fund Operating Expenses do not correlate to the ratio of expenses to average net assets given in the Fund’s most recent annual report, which does not include Acquired Fund Fees and Expenses.

Example:

This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

	1 Year	3 Years	5 Years	10 Years
Class K Shares	$38	$121	$212	$479

Table of Contents

Portfolio Turnover:

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the Example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 556% of the average value of its portfolio.

Principal Investment Strategies of the Fund

The Fund typically invests more than 90% of its assets in a diversified portfolio of fixed-income securities such as corporate bonds and notes, mortgage-backed securities, asset-backed securities, convertible securities, preferred securities and government obligations. Both U.S. and foreign companies and governments may issue these securities. Under normal circumstances, the Fund invests at least 80% of its assets in bonds and invests primarily in investment grade fixed-income securities. The Fund may invest in fixed-income securities of any duration or maturity.

The Fund may invest up to 30% of its net assets in securities of foreign issuers, of which 20% (as a percentage of the Fund’s net assets) may be in emerging markets issuers. Investments in U.S. dollar-denominated securities of foreign issuers, excluding issuers from emerging markets, are permitted beyond the 30% limit. This means that the Fund may invest in such U.S. dollar-denominated securities of foreign issuers without limit. The Fund may also invest in derivative securities for hedging purposes or to increase the return on its investments. The Fund may also invest in credit-linked notes, credit-linked trust certificates, structured notes, or other instruments evidencing interests in special purpose vehicles, trusts, or other entities that hold or represent interests in fixed-income securities. The Fund may also enter into reverse repurchase agreements and mortgage dollar rolls.

The Fund may invest up to 20% of its net assets in fixed-income securities that are rated below investment grade by the Nationally Recognized Statistical Rating Organizations (“NRSROs”), including Moody’s Investor Service, Inc., S&P Global Ratings or Fitch Ratings, Inc., or in unrated securities of equivalent credit quality. Split rated bonds will be considered to have the higher credit rating.

The Fund may invest up to 15% of its net assets in collateralized debt obligations (“CDOs”), of which 10% (as a percentage of the Fund’s net assets) may be in collateralized loan obligations (“CLOs”). CDOs are types of asset-backed securities. CLOs are ordinarily issued by a trust or other special purpose entity and are typically collateralized by a pool of loans, which may include, among others, domestic and non-U.S. senior secured loans, senior unsecured loans, and subordinate corporate loans, including loans that may be rated below investment grade or equivalent unrated loans, held by such issuer.

The Fund is a “feeder” fund that invests all of its assets in a corresponding “master” portfolio, the Master Total Return Portfolio (previously defined as the “Master Portfolio”), a series of the Master Bond LLC (the “Master LLC”), a mutual fund that has the same investment objectives and strategies as the Fund. All investments will be made at the level of the Master Portfolio. This structure is sometimes called a “master/feeder” structure. The Fund’s investment results will correspond directly to the investment results of the underlying Master Portfolio in which it invests. For simplicity, this prospectus uses the term “Fund” to include the Master Portfolio.

The Fund may seek to provide exposure to the investment returns of real assets that trade in the commodity markets through investment in commodity-linked derivative instruments and investment vehicles that exclusively invest in commodities such as ETFs, which are designed to provide this exposure without direct investment in physical commodities.

Principal Risks of Investing in the Fund

Risk is inherent in all investing. The value of your investment in the Fund, as well as the amount of return you receive on your investment, may fluctuate significantly from day to day and over time. You may lose part or all of your investment in the Fund or your investment may not perform as well as other similar investments. The following is a summary description of principal risks of investing in the Fund. The order of the below risk factors does not indicate the significance of any particular risk factor.

■

Collateralized Debt Obligations Risk — In addition to the typical risks associated with fixed-income securities and asset-backed securities, CDOs, including CLOs, carry additional risks including, but not limited to: (i) the possibility that distributions from collateral securities will not be adequate to make interest or other payments; (ii) the risk that the collateral may default or decline in value or be downgraded, if rated by a nationally recognized statistical rating organization; (iii) the Fund may invest in tranches of CDOs that are subordinate to other tranches; (iv) the structure and complexity of the transaction and the legal documents could lead to disputes among investors regarding the

Table of Contents

	characterization of proceeds; (v) the investment return achieved by the Fund could be significantly different than those predicted by financial models; (vi) the lack of a readily available secondary market for CDOs; (vii) the risk of forced “fire sale” liquidation due to technical defaults such as coverage test failures; and (viii) the CDO’s manager may perform poorly.
■	Commodities Related Investments Risk — Exposure to the commodities markets may subject the Fund to greater volatility than investments in traditional securities. The value of commodity-linked derivative investments may be affected by changes in overall market movements, commodity index volatility, changes in interest rates, or factors affecting a particular industry or commodity, such as drought, floods, weather, embargoes, tariffs and international economic, political and regulatory developments.
■	Convertible Securities Risk — The market value of a convertible security performs like that of a regular debt security; that is, if market interest rates rise, the value of a convertible security usually falls. In addition, convertible securities are subject to the risk that the issuer will not be able to pay interest or dividends when due, and their market value may change based on changes in the issuer’s credit rating or the market’s perception of the issuer’s creditworthiness. Since it derives a portion of its value from the common stock into which it may be converted, a convertible security is also subject to the same types of market and issuer risks that apply to the underlying common stock.
■	Debt Securities Risk — Debt securities, such as bonds, involve interest rate risk, credit risk, extension risk, and prepayment risk, among other things.
	Interest Rate Risk — The market value of bonds and other fixed-income securities changes in response to interest rate changes and other factors. Interest rate risk is the risk that prices of bonds and other fixed-income securities will increase as interest rates fall and decrease as interest rates rise.
	The Fund may be subject to a greater risk of rising interest rates due to the current period of historically low rates. For example, if interest rates increase by 1%, assuming a current portfolio duration of ten years, and all other factors being equal, the value of the Fund’s investments would be expected to decrease by 10%. The magnitude of these fluctuations in the market price of bonds and other fixed-income securities is generally greater for those securities with longer maturities. Fluctuations in the market price of the Fund’s investments will not affect interest income derived from instruments already owned by the Fund, but will be reflected in the Fund’s net asset value. The Fund may lose money if short-term or long-term interest rates rise sharply in a manner not anticipated by Fund management.
	To the extent the Fund invests in debt securities that may be prepaid at the option of the obligor (such as mortgage-backed securities), the sensitivity of such securities to changes in interest rates may increase (to the detriment of the Fund) when interest rates rise. Moreover, because rates on certain floating rate debt securities typically reset only periodically, changes in prevailing interest rates (and particularly sudden and significant changes) can be expected to cause some fluctuations in the net asset value of the Fund to the extent that it invests in floating rate debt securities.
	These basic principles of bond prices also apply to U.S. Government securities. A security backed by the “full faith and credit” of the U.S. Government is guaranteed only as to its stated interest rate and face value at maturity, not its current market price. Just like other fixed-income securities, government-guaranteed securities will fluctuate in value when interest rates change.
	A general rise in interest rates has the potential to cause investors to move out of fixed-income securities on a large scale, which may increase redemptions from funds that hold large amounts of fixed-income securities. Heavy redemptions could cause the Fund to sell assets at inopportune times or at a loss or depressed value and could hurt the Fund’s performance.
	Credit Risk — Credit risk refers to the possibility that the issuer of a debt security (i.e., the borrower) will not be able to make payments of interest and principal when due. Changes in an issuer’s credit rating or the market’s perception of an issuer’s creditworthiness may also affect the value of the Fund’s investment in that issuer. The degree of credit risk depends on both the financial condition of the issuer and the terms of the obligation.
	Extension Risk — When interest rates rise, certain obligations will be paid off by the obligor more slowly than anticipated, causing the value of these obligations to fall.
	Prepayment Risk — When interest rates fall, certain obligations will be paid off by the obligor more quickly than originally anticipated, and the Fund may have to invest the proceeds in securities with lower yields.
■	Derivatives Risk — The Fund’s use of derivatives may increase its costs, reduce the Fund’s returns and/or increase volatility. Derivatives involve significant risks, including:

Table of Contents

	Volatility Risk — Volatility is defined as the characteristic of a security, an index or a market to fluctuate significantly in price within a short time period. A risk of the Fund’s use of derivatives is that the fluctuations in their values may not correlate with the overall securities markets.
	Counterparty Risk — Derivatives are also subject to counterparty risk, which is the risk that the other party in the transaction will not fulfill its contractual obligation.
	Market and Illiquidity Risk — The possible lack of a liquid secondary market for derivatives and the resulting inability of the Fund to sell or otherwise close a derivatives position could expose the Fund to losses and could make derivatives more difficult for the Fund to value accurately.
	Valuation Risk — Valuation may be more difficult in times of market turmoil since many investors and market makers may be reluctant to purchase complex instruments or quote prices for them.
	Hedging Risk — Hedges are sometimes subject to imperfect matching between the derivative and the underlying security, and there can be no assurance that the Fund’s hedging transactions will be effective. The use of hedging may result in certain adverse tax consequences.
	Tax Risk — Certain aspects of the tax treatment of derivative instruments, including swap agreements and commodity-linked derivative instruments, are currently unclear and may be affected by changes in legislation, regulations or other legally binding authority. Such treatment may be less favorable than that given to a direct investment in an underlying asset and may adversely affect the timing, character and amount of income the Fund realizes from its investments.
	Regulatory Risk — Derivative contracts, including, without limitation, swaps, currency forwards and non-deliverable forwards, are subject to regulation under the Dodd-Frank Wall Street Reform and Consumer Protection Act (the “Dodd-Frank Act”) in the United States and under comparable regimes in Europe, Asia and other non-U.S. jurisdictions. Under the Dodd-Frank Act, certain derivatives are subject to margin requirements and swap dealers are required to collect margin from the Fund with respect to such derivatives. Specifically, regulations are now in effect that require swap dealers to post and collect variation margin (comprised of specified liquid instruments and subject to a required haircut) in connection with trading of over-the-counter (“OTC”) swaps with the Fund. Shares of investment companies (other than certain money market funds) may not be posted as collateral under these regulations. Requirements for posting of initial margin in connection with OTC swaps will be phased-in through at least 2021. In addition, regulations adopted by global prudential regulators that are now in effect require certain bank-regulated counterparties and certain of their affiliates to include in certain financial contracts, including many derivatives contracts, terms that delay or restrict the rights of counterparties, such as the Fund, to terminate such contracts, foreclose upon collateral, exercise other default rights or restrict transfers of credit support in the event that the counterparty and/or its affiliates are subject to certain types of resolution or insolvency proceedings. The implementation of these requirements with respect to derivatives, as well as regulations under the Dodd-Frank Act regarding clearing, mandatory trading and margining of other derivatives, may increase the costs and risks to the Fund of trading in these instruments and, as a result, may affect returns to investors in the Fund.
	On October 28, 2020, the Securities and Exchange Commission adopted new regulations governing the use of derivatives by registered investment companies (“Rule 18f-4”). The Fund will be required to implement and comply with Rule 18f-4 by August 19, 2022. Once implemented, Rule 18f-4 will impose limits on the amount of derivatives a fund can enter into, eliminate the asset segregation framework currently used by funds to comply with Section 18 of the Investment Company Act of 1940, as amended, treat derivatives as senior securities so that a failure to comply with the limits would result in a statutory violation and require funds whose use of derivatives is more than a limited specified exposure amount to establish and maintain a comprehensive derivatives risk management program and appoint a derivatives risk manager.
■	Dollar Rolls Risk — Dollar rolls involve the risk that the market value of the securities that the Fund is committed to buy may decline below the price of the securities the Fund has sold. These transactions may involve leverage.
■	Emerging Markets Risk — Emerging markets are riskier than more developed markets because they tend to develop unevenly and may never fully develop. Investments in emerging markets may be considered speculative. Emerging markets are more likely to experience hyperinflation and currency devaluations, which adversely affect returns to U.S. investors. In addition, many emerging securities markets have far lower trading volumes and less liquidity than developed markets.
■	Foreign Securities Risk — Foreign investments often involve special risks not present in U.S. investments that can increase the chances that the Fund will lose money. These risks include:

■	The Fund generally holds its foreign securities and cash in foreign banks and securities depositories, which may be recently organized or new to the foreign custody business and may be subject to only limited or no regulatory oversight.

Table of Contents

■	Changes in foreign currency exchange rates can affect the value of the Fund’s portfolio.
■	The economies of certain foreign markets may not compare favorably with the economy of the United States with respect to such issues as growth of gross national product, reinvestment of capital, resources and balance of payments position.
■	The governments of certain countries may prohibit or impose substantial restrictions on foreign investments in their capital markets or in certain industries.
■	Many foreign governments do not supervise and regulate stock exchanges, brokers and the sale of securities to the same extent as does the United States and may not have laws to protect investors that are comparable to U.S. securities laws.
■	Settlement and clearance procedures in certain foreign markets may result in delays in payment for or delivery of securities not typically associated with settlement and clearance of U.S. investments.
■	The Fund’s claims to recover foreign withholding taxes may not be successful, and if the likelihood of recovery of foreign withholding taxes materially decreases, due to, for example, a change in tax regulation or approach in the foreign country, accruals in the Fund’s net asset value for such refunds may be written down partially or in full, which will adversely affect the Fund’s net asset value.
■	The European financial markets have recently experienced volatility and adverse trends due to concerns about economic downturns in, or rising government debt levels of, several European countries. These events may spread to other countries in Europe. These events may affect the value and liquidity of certain of the Fund’s investments.

■	High Portfolio Turnover Risk — The Fund may engage in active and frequent trading of its portfolio securities. High portfolio turnover (more than 100%) may result in increased transaction costs to the Fund, including brokerage commissions, dealer mark-ups and other transaction costs on the sale of the securities and on reinvestment in other securities. The sale of Fund portfolio securities may result in the realization and/or distribution to shareholders of higher capital gains or losses as compared to a fund with less active trading policies. These effects of higher than normal portfolio turnover may adversely affect Fund performance. In addition, investment in mortgage dollar rolls and participation in to-be-announced (“TBA”) transactions may significantly increase the Fund’s portfolio turnover rate. A TBA transaction is a method of trading mortgage-backed securities where the buyer and seller agree upon general trade parameters such as agency, settlement date, par amount, and price at the time the contract is entered into but the mortgage-backed securities are delivered in the future, generally 30 days later.
■	Junk Bonds Risk — Although junk bonds generally pay higher rates of interest than investment grade bonds, junk bonds are high risk investments that are considered speculative and may cause income and principal losses for the Fund.
■	Leverage Risk — Some transactions may give rise to a form of economic leverage. These transactions may include, among others, derivatives, and may expose the Fund to greater risk and increase its costs. The use of leverage may cause the Fund to liquidate portfolio positions when it may not be advantageous to do so to satisfy its obligations or to meet any required asset segregation requirements. Increases and decreases in the value of the Fund’s portfolio will be magnified when the Fund uses leverage.
■	Market Risk and Selection Risk — Market risk is the risk that one or more markets in which the Fund invests will go down in value, including the possibility that the markets will go down sharply and unpredictably. The value of a security or other asset may decline due to changes in general market conditions, economic trends or events that are not specifically related to the issuer of the security or other asset, or factors that affect a particular issuer or issuers, exchange, country, group of countries, region, market, industry, group of industries, sector or asset class. Local, regional or global events such as war, acts of terrorism, the spread of infectious illness or other public health issues like pandemics or epidemics, recessions, or other events could have a significant impact on the Fund and its investments. Selection risk is the risk that the securities selected by Fund management will underperform the markets, the relevant indices or the securities selected by other funds with similar investment objectives and investment strategies. This means you may lose money.
	A recent outbreak of an infectious coronavirus has developed into a global pandemic that has resulted in numerous disruptions in the market and has had significant economic impact leaving general concern and uncertainty. The impact of this coronavirus, and other epidemics and pandemics that may arise in the future, could affect the economies of many nations, individual companies and the market in general ways that cannot necessarily be foreseen at the present time.
■	Mortgage- and Asset-Backed Securities Risks — Mortgage- and asset-backed securities represent interests in “pools” of mortgages or other assets, including consumer loans or receivables held in trust. Mortgage- and asset-backed securities are subject to credit, interest rate, prepayment and extension risks. These securities also are

Table of Contents

	subject to risk of default on the underlying mortgage or asset, particularly during periods of economic downturn. Small movements in interest rates (both increases and decreases) may quickly and significantly reduce the value of certain mortgage-backed securities.
■	Preferred Securities Risk — Preferred securities may pay fixed or adjustable rates of return. Preferred securities are subject to issuer-specific and market risks applicable generally to equity securities. In addition, a company’s preferred securities generally pay dividends only after the company makes required payments to holders of its bonds and other debt. For this reason, the value of preferred securities will usually react more strongly than bonds and other debt to actual or perceived changes in the company’s financial condition or prospects. Preferred securities of smaller companies may be more vulnerable to adverse developments than preferred securities of larger companies.
■	Reverse Repurchase Agreements Risk — Reverse repurchase agreements involve the sale of securities held by the Fund with an agreement to repurchase the securities at an agreed-upon price, date and interest payment. Reverse repurchase agreements involve the risk that the other party may fail to return the securities in a timely manner or at all. The Fund could lose money if it is unable to recover the securities and the value of the collateral held by the Fund, including the value of the investments made with cash collateral, is less than the value of the securities. These events could also trigger adverse tax consequences for the Fund. In addition, reverse repurchase agreements involve the risk that the interest income earned in the investment of the proceeds will be less than the interest expense.
■	Sovereign Debt Risk — Sovereign debt instruments are subject to the risk that a governmental entity may delay or refuse to pay interest or repay principal on its sovereign debt, due, for example, to cash flow problems, insufficient foreign currency reserves, political considerations, the relative size of the governmental entity’s debt position in relation to the economy or the failure to put in place economic reforms required by the International Monetary Fund or other multilateral agencies.
■	Structured Notes Risk — Structured notes and other related instruments purchased by the Fund are generally privately negotiated debt obligations where the principal and/or interest is determined by reference to the performance of a specific asset, benchmark asset, market or interest rate (“reference measure”). The purchase of structured notes exposes the Fund to the credit risk of the issuer of the structured product. Structured notes may be leveraged, increasing the volatility of each structured note’s value relative to the change in the reference measure. Structured notes may also be less liquid and more difficult to price accurately than less complex securities and instruments or more traditional debt securities.
■	U.S. Government Issuer Risk — Treasury obligations may differ in their interest rates, maturities, times of issuance and other characteristics. Obligations of U.S. Government agencies and authorities are supported by varying degrees of credit but generally are not backed by the full faith and credit of the U.S. Government. No assurance can be given that the U.S. Government will provide financial support to its agencies and authorities if it is not obligated by law to do so.

Performance Information

The information shows you how the Fund’s performance has varied year by year and provides some indication of the risks of investing in the Fund. The table compares the Fund’s performance to that of the Bloomberg Barclays U.S. Aggregate Bond Index. Effective September 1, 2015, the Board of Directors of the Corporation approved the redesignation of BlackRock Shares of the Fund as Class K Shares. Performance for Class K Shares prior to September 1, 2015 reflects the performance of the share class when it was classified as BlackRock Shares. To the extent that dividends and distributions have been paid by the Fund, the performance information for the Fund in the chart and table assumes reinvestment of the dividends and distributions. As with all such investments, past performance (before and after taxes) is not an indication of future results. The table includes all applicable fees. If the Fund’s investment manager and its affiliates had not waived or reimbursed certain Fund expenses during these periods, the Fund’s returns would have been lower. Updated information on the Fund’s performance, including its current net asset value, can be obtained by visiting http://www.blackrock.com or can be obtained by phone at 800-882-0052.

Table of Contents

Class K Shares

ANNUAL TOTAL RETURNS

BlackRock Total Return Fund
As of 12/31

During the ten-year period shown in the bar chart, the highest return for a quarter was 5.65% (quarter ended June 30, 2020) and the lowest return for a quarter was -2.36% (quarter ended December 31, 2016).

As of 12/31/20 Average Annual Total Returns	1 Year	5 Years	10 Years
BlackRock Total Return Fund — Class K Shares
Return Before Taxes	9.09%	5.13%	4.87%
Return After Taxes on Distributions	6.68%	3.55%	3.29%
Return After Taxes on Distributions and Sale of Fund Shares	5.66%	3.27%	3.09%
Bloomberg Barclays U.S. Aggregate Bond Index (Reflects no deduction for fees, expenses or taxes)	7.51%	4.44%	3.84%

After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts.

Investment Manager

The Fund’s investment manager is BlackRock Advisors, LLC (previously defined as “BlackRock”). The Fund’s sub-advisers are BlackRock International Limited and BlackRock (Singapore) Limited. Where applicable, the use of the term BlackRock also refers to the Fund’s sub-advisers.

Portfolio Managers

Name	Portfolio Manager of the Fund Since	Title
Rick Rieder	2010	Chief Investment Officer of Global Fixed Income, Head of Global Allocation Investment Team in the Multi-Asset Strategies Group, member of Global Operating Committee and Chairman of the BlackRock, Inc. firmwide Investment Council
Bob Miller	2011	Managing Director of BlackRock, Inc.
David Rogal	2017	Managing Director of BlackRock, Inc.

Purchase and Sale of Fund Shares

Class K Shares of the Fund are available only to (i) certain employee benefit plans, such as health savings accounts, and certain employer-sponsored retirement plans (not including SEP IRAs, SIMPLE IRAs and SARSEPs) (collectively, “Employer-Sponsored Retirement Plans”), (ii) collective trust funds, investment companies and other pooled investment vehicles, each of which may purchase shares of the Fund through a Financial Intermediary that has entered

Table of Contents

into an agreement with the Fund’s distributor to purchase such shares, (iii) “Institutional Investors,” which include, but are not limited to, endowments, foundations, family offices, banks and bank trusts, local, city, and state governmental institutions, corporations and insurance company separate accounts, each of which may purchase shares of the Fund through a Financial Intermediary that has entered into an agreement with the Fund’s distributor to purchase such shares, (iv) clients of private banks that purchase shares of the Fund through a Financial Intermediary that has entered into an agreement with the Fund’s distributor to sell such shares, (v) fee-based advisory platforms of a Financial Intermediary that (a) has specifically acknowledged in a written agreement with the Fund’s distributor and/or its affiliate(s) that the Financial Intermediary shall offer such shares to fee-based advisory clients through an omnibus account held at the Fund or (b) transacts in the Fund’s shares through another intermediary that has executed such an agreement and (vi) any other investors who met the eligibility criteria for BlackRock Shares or Class K Shares prior to August 15, 2016 and have continually held Class K Shares of the Fund in the same account since August 15, 2016.

You may purchase or redeem shares of the Fund each day the New York Stock Exchange is open. Purchase orders may also be placed by calling (800) 537-4942, by mail (c/o BlackRock, P.O. Box 9819, Providence, Rhode Island 02940-8019), or online at www.blackrock.com. Institutional Investors are subject to a $5 million minimum initial investment requirement. Other investors, including Employer-Sponsored Retirement Plans, have no minimum initial investment requirement. There is no minimum investment amount for additional purchases.

Tax Information

Different income tax rules apply depending on whether you are invested through a qualified tax-exempt plan described in section 401(a) of the Internal Revenue Code of 1986, as amended. If you are invested through such a plan (and Fund shares are not “debt-financed property” to the plan), then the dividends paid by the Fund and the gain realized from a redemption or exchange of Fund shares will generally not be subject to U.S. federal income taxes until you withdraw or receive distributions from the plan. If you are not invested through such a plan, then the Fund’s dividends and gain from a redemption or exchange may be subject to U.S. federal income taxes and may be taxed as ordinary income or capital gains, unless you are a tax-exempt investor.

Payments to Broker/Dealers and Other Financial Intermediaries

If you purchase shares of the Fund through a Financial Intermediary, the Fund and BlackRock Investments, LLC, the Fund’s distributor, or its affiliates may pay the Financial Intermediary for the sale of Fund shares and related services. These payments may create a conflict of interest by influencing the Financial Intermediary and your individual financial professional to recommend the Fund over another investment.

Class K Shares are only available through a Financial Intermediary if the Financial Intermediary will not receive from Fund assets, or the Fund’s distributor’s or an affiliate’s resources, any commission payments, shareholder servicing fees (including sub-transfer agent and networking fees), or distribution fees (including Rule 12b-1 fees) with respect to assets invested in Class K Shares.

Ask your individual financial professional or visit your Financial Intermediary’s website for more information.

Table of Contents

Details About the Fund

Included in this prospectus are sections that tell you about buying and selling shares, management information, shareholder features of the BlackRock Total Return Fund (the “Fund”) and your rights as a shareholder.

The Fund is a “feeder” fund that invests all of its assets in a “master” portfolio, the Master Total Return Portfolio (the “Master Portfolio”) of Master Bond LLC (the “Master LLC”), that has the same investment objective and strategies as the Fund. All investments will be made at the Master Portfolio level. This structure is sometimes called a “master/feeder” structure. The Fund’s investment results will correspond directly to the investment results of the Master Portfolio. For simplicity, this prospectus uses the term “Fund” to include the Master Portfolio.

How the Fund Invests

Investment Objective

The investment objective of the Fund is to realize a total return that exceeds that of the Bloomberg Barclays U.S. Aggregate Bond Index.

This investment objective is a fundamental policy of the Fund and may not be changed without approval of a majority of the Fund’s outstanding voting securities, as defined in the Investment Company Act of 1940, as amended (the “Investment Company Act”).

Investment Process

The Fund invests primarily in a diversified portfolio of fixed-income securities, such as corporate bonds and notes, mortgage-backed and asset-backed securities, convertible securities, preferred securities and government debt obligations.

Principal Investment Strategies

The Fund typically invests more than 90% of its assets in a diversified portfolio of fixed-income securities. The fixed-income securities in which the Fund invests include:

■	U.S. Government debt securities
■	Corporate debt securities issued by U.S. and foreign companies
■	Asset-backed securities
■	Mortgage-backed securities
■	Preferred securities issued by U.S. and foreign companies
■	Corporate debt securities and preferred securities convertible into common stock
■	Foreign sovereign debt instruments
■	Money market securities

Under normal circumstances, the Fund invests at least 80% of its assets in bonds. This 80% policy is a non-fundamental policy of the Fund and may not be changed without 60 days’ prior notice to shareholders. The Fund invests primarily in fixed-income securities that are rated in the four highest rating categories by at least one of the recognized rating agencies (including Baa or better by Moody’s Investor Service, Inc. (“Moody’s”) or BBB or better by S&P Global Ratings (“S&P”) or Fitch Ratings (“Fitch”)) or determined by the Fund’s management team to be of similar quality. Securities rated in any of the four highest rating categories are known as “investment grade” securities.

The Fund may invest in various types of mortgage-backed securities. Mortgage-backed securities represent the right to receive a portion of principal and/or interest payments made on a pool of residential or commercial mortgage loans. Mortgage-backed securities frequently react differently to changes in interest rates than other fixed-income securities. The Fund may also enter into reverse repurchase agreements and mortgage dollar rolls.

Table of Contents

The Fund may invest in fixed-income securities of any duration or maturity. Fixed-income securities frequently have redemption features that permit an issuer to repurchase the security from the Fund at certain times prior to maturity at a specified price, which is generally the amount due at maturity. In many cases, when interest rates go down, issuers redeem fixed-income securities that allow for redemption. When an issuer redeems fixed-income securities, the Fund may receive less than the market value of the securities prior to redemption. In addition, the Fund may have to invest the proceeds in new fixed-income securities with lower yields and therefore lose expected future income.

The Fund may use derivatives, including, but not limited to, interest rate, total return and credit default swaps, options, futures, options on futures and swaps, for hedging purposes, as well as to increase the return on its portfolio investments. Derivatives are financial instruments whose value is derived from another security or an index such as the Bloomberg Barclays U.S. Aggregate Bond Index or the CSFB High Yield Index. The Fund may also invest in credit-linked notes, credit-linked trust certificates, structured notes, or other instruments evidencing interests in special purpose vehicles, trusts, or other entities that hold or represent interests in fixed-income securities.

The Fund may invest up to 20% of its net assets in fixed-income securities that are rated below investment grade by the Nationally Recognized Statistical Rating Organizations (“NRSROs”), including Moody’s, S&P or Fitch or in unrated securities of equivalent credit quality. Split rated bonds will be considered to have the higher credit rating.

The Fund may seek to provide exposure to the investment returns of real assets that trade in the commodity markets through investment in commodity-linked derivative instruments and investment vehicles that exclusively invest in precious metals, which are designed to provide this exposure without direct investment in physical commodities.

Other Strategies

In addition to the principal strategies discussed above, the Fund may also invest or engage in the following investments/strategies:

■	Borrowing — The Fund may borrow up to the limits set forth under the Investment Company Act, the rules and regulations thereunder and any applicable exemptive relief.
■	Illiquid Investments — The Fund may invest up to an aggregate amount of 15% of its net assets in illiquid investments. An illiquid investment is any investment that the Fund reasonably expects cannot be sold or disposed of in current market conditions in seven calendar days or less without the sale or disposition significantly changing the market value of the investment.
■	Indexed and Inverse Securities — The Fund may invest in securities the potential return of which is based on the change in a specified interest rate or equity index (an “indexed security”). The Fund may also invest in securities whose return is inversely related to changes in an interest rate or index (“inverse securities”). In general, the return on inverse securities will decrease when the underlying index or interest rate goes up and increase when that index or interest rate goes down.
■	Investment Companies — The Fund has the ability to invest in other investment companies, such as exchange-traded funds (“ETFs”), unit investment trusts, and open-end and closed-end funds. The Fund may invest in affiliated investment companies, including affiliated money market funds and affiliated ETFs.
■	Repurchase Agreements and Purchase and Sale Contracts — The Fund may enter into certain types of repurchase agreements or purchase and sale contracts. Under a repurchase agreement, the seller agrees to repurchase a security at a mutually agreed-upon time and price. A purchase and sale contract is similar to a repurchase agreement, but purchase and sale contracts also provide that the purchaser receives any interest on the security paid during the period.
■	Restricted Securities — Restricted securities are securities that cannot be offered for public resale unless registered under the applicable securities laws or that have a contractual restriction that prohibits or limits their resale. They may include Rule 144A securities, which are privately placed securities that can be resold to qualified institutional buyers but not to the general public, and securities of U.S. and non-U.S. issuers that are offered pursuant to Regulation S under the Securities Act of 1933, as amended.
■	Securities Lending — The Fund may lend securities with a value up to 33¹⁄3% of its total assets to financial institutions that provide cash or securities issued or guaranteed by the U.S. Government as collateral.

Table of Contents

■	Standby Commitment Agreements — Standby commitment agreements commit the Fund, for a stated period of time, to purchase a stated amount of securities that may be issued and sold to the Fund at the option of the issuer.
■	Temporary Defensive Strategies — For temporary defensive purposes, the Fund may restrict the markets in which it invests and may invest without limitation in cash, cash equivalents, money market securities, such as U.S. Treasury and agency obligations, other U.S. Government securities, short term debt obligations of corporate issuers, certificates of deposit, bankers’ acceptances, commercial paper (short term, unsecured, negotiable promissory notes of a domestic or foreign issuer) or other high quality fixed-income securities. The yield on such securities may be lower than the yield on lower-rated fixed-income securities. Normally a portion of the Fund’s assets would be held in these securities in anticipation of investment opportunities or to meet redemptions. Investments in money market securities can be sold easily and have limited risk of loss. Temporary defensive positions may limit the potential for an increase in the value of the Fund’s shares and may affect the Fund’s ability to achieve its investment objectives.
■	When-Issued and Delayed Delivery Securities and Forward Commitments — The purchase or sale of securities on a when-issued basis or on a delayed delivery basis or through a forward commitment involves the purchase or sale of securities by the Fund at an established price with payment and delivery taking place in the future. The Fund enters into these transactions to obtain what is considered an advantageous price to the Fund at the time of entering into the transaction.

ABOUT THE PORTFOLIO MANAGEMENT OF THE FUND

The Fund is managed by a team of financial professionals. Rick Rieder, Bob Miller and David Rogal are the portfolio managers and are jointly and primarily responsible for the day-to-day management of the Fund. Please see “Management of the Fund — Portfolio Manager Information” for additional information about the portfolio management team.

Investment Risks

This section contains a discussion of the general risks of investing in the Fund. The “Investment Objectives and Policies” section in the Statement of Additional Information (“SAI”) also includes more information about the Fund, its investments and the related risks. As with any fund, there can be no guarantee that the Fund will meet its investment objective or that the Fund’s performance will be positive for any period of time. An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or by any bank or governmental agency. The order of the below risk factors does not indicate the significance of any particular risk factor.

Principal Risks of Investing in the Fund:

■	Collateralized Debt Obligations Risk — In addition to the typical risks associated with fixed-income securities and asset-backed securities, CDOs, including CLOs, carry additional risks including, but not limited to: (i) the possibility that distributions from collateral securities will not be adequate to make interest or other payments; (ii) the risk that the collateral may default or decline in value or be downgraded, if rated by a nationally recognized statistical rating organization; (iii) the Fund may invest in tranches of CDOs that are subordinate to other tranches; (iv) the structure and complexity of the transaction and the legal documents could lead to disputes among investors regarding the characterization of proceeds; (v) the investment return achieved by the Fund could be significantly different than those predicted by financial models; (vi) the lack of a readily available secondary market for CDOs; (vii) the risk of forced “fire sale” liquidation due to technical defaults such as coverage test failures; and (viii) the CDO’s manager may perform poorly.
■	Commodities Related Investments Risk — Exposure to the commodities markets may subject the Fund to greater volatility than investments in traditional securities. The value of commodity-linked derivative investments may be affected by changes in overall market movements, commodity index volatility, changes in interest rates, or factors affecting a particular industry or commodity, such as drought, floods, weather, embargoes, tariffs and international economic, political and regulatory developments.
■	Convertible Securities Risk — The market value of a convertible security performs like that of a regular debt security; that is, if market interest rates rise, the value of a convertible security usually falls. In addition, convertible securities are subject to the risk that the issuer will not be able to pay interest or dividends when due, and their market value may change based on changes in the issuer’s credit rating or the market’s perception of the issuer’s

Table of Contents

	creditworthiness. Since it derives a portion of its value from the common stock into which it may be converted, a convertible security is also subject to the same types of market and issuer risks that apply to the underlying common stock.
■	Debt Securities Risk — Debt securities, such as bonds, involve interest rate risk, credit risk, extension risk, and prepayment risk, among other things.
	Interest Rate Risk — The market value of bonds and other fixed-income securities changes in response to interest rate changes and other factors. Interest rate risk is the risk that prices of bonds and other fixed-income securities will increase as interest rates fall and decrease as interest rates rise.
	The Fund may be subject to a greater risk of rising interest rates due to the current period of historically low rates. For example, if interest rates increase by 1%, assuming a current portfolio duration of ten years, and all other factors being equal, the value of the Fund’s investments would be expected to decrease by 10%. The magnitude of these fluctuations in the market price of bonds and other fixed-income securities is generally greater for those securities with longer maturities. Fluctuations in the market price of the Fund’s investments will not affect interest income derived from instruments already owned by the Fund, but will be reflected in the Fund’s net asset value. The Fund may lose money if short-term or long-term interest rates rise sharply in a manner not anticipated by Fund management.
	To the extent the Fund invests in debt securities that may be prepaid at the option of the obligor (such as mortgage-backed securities), the sensitivity of such securities to changes in interest rates may increase (to the detriment of the Fund) when interest rates rise. Moreover, because rates on certain floating rate debt securities typically reset only periodically, changes in prevailing interest rates (and particularly sudden and significant changes) can be expected to cause some fluctuations in the net asset value of the Fund to the extent that it invests in floating rate debt securities.
	These basic principles of bond prices also apply to U.S. Government securities. A security backed by the “full faith and credit” of the U.S. Government is guaranteed only as to its stated interest rate and face value at maturity, not its current market price. Just like other fixed-income securities, government-guaranteed securities will fluctuate in value when interest rates change.
	Following the financial crisis that began in 2007, the Federal Reserve has attempted to stabilize the economy and support the economic recovery by keeping the federal funds rate (the interest rate at which depository institutions lend reserve balances to other depository institutions overnight) at or near zero percent. In addition, as part of its monetary stimulus program known as quantitative easing, the Federal Reserve has purchased on the open market large quantities of securities issued or guaranteed by the U.S. Government, its agencies or instrumentalities. As the Federal Reserve “tapers” or reduces the amount of securities it purchases pursuant to quantitative easing, and/or if the Federal Reserve raises the federal funds rate, there is a risk that interest rates will rise. A general rise in interest rates has the potential to cause investors to move out of fixed-income securities on a large scale, which may increase redemptions from mutual funds that hold large amounts of fixed-income securities. Heavy redemptions could cause the Fund to sell assets at inopportune times or at a loss or depressed value and could hurt the Fund’s performance.
	During periods of very low or negative interest rates, the Fund may be unable to maintain positive returns. Certain countries have recently experienced negative interest rates on certain fixed-income instruments. Very low or negative interest rates may magnify interest rate risk. Changing interest rates, including rates that fall below zero, may have unpredictable effects on markets, may result in heightened market volatility and may detract from Fund performance to the extent the Fund is exposed to such interest rates.
	Credit Risk — Credit risk refers to the possibility that the issuer of a debt security (i.e., the borrower) will not be able to make payments of interest and principal when due. Changes in an issuer’s credit rating or the market’s perception of an issuer’s creditworthiness may also affect the value of the Fund’s investment in that issuer. The degree of credit risk depends on both the financial condition of the issuer and the terms of the obligation.
	Extension Risk — When interest rates rise, certain obligations will be paid off by the obligor more slowly than anticipated, causing the value of these obligations to fall. Rising interest rates tend to extend the duration of securities, making them more sensitive to changes in interest rates. The value of longer-term securities generally changes more in response to changes in interest rates than shorter-term securities. As a result, in a period of rising interest rates, securities may exhibit additional volatility and may lose value.
	Prepayment Risk — When interest rates fall, certain obligations will be paid off by the obligor more quickly than originally anticipated, and the Fund may have to invest the proceeds in securities with lower yields. In periods of falling interest rates, the rate of prepayments tends to increase (as does price fluctuation) as borrowers are

Table of Contents

	motivated to pay off debt and refinance at new lower rates. During such periods, reinvestment of the prepayment proceeds by the management team will generally be at lower rates of return than the return on the assets that were prepaid. Prepayment reduces the yield to maturity and the average life of the security.
■	Derivatives Risk — The Fund’s use of derivatives may increase its costs, reduce the Fund’s returns and/or increase volatility. Derivatives involve significant risks, including:
	Volatility Risk — The Fund’s use of derivatives may reduce the Fund’s returns and/or increase volatility. Volatility is defined as the characteristic of a security, an index or a market to fluctuate significantly in price within a short time period. A risk of the Fund’s use of derivatives is that the fluctuations in their values may not correlate with the overall securities markets.
	Counterparty Risk — Derivatives are also subject to counterparty risk, which is the risk that the other party in the transaction will not fulfill its contractual obligation.
	Market and Illiquidity Risk — Some derivatives are more sensitive to interest rate changes and market price fluctuations than other securities. The possible lack of a liquid secondary market for derivatives and the resulting inability of the Fund to sell or otherwise close a derivatives position could expose the Fund to losses and could make derivatives more difficult for the Fund to value accurately. The Fund could also suffer losses related to its derivatives positions as a result of unanticipated market movements, which losses are potentially unlimited. Finally, BlackRock may not be able to predict correctly the direction of securities prices, interest rates and other economic factors, which could cause the Fund’s derivatives positions to lose value.
	Valuation Risk — Valuation may be more difficult in times of market turmoil since many investors and market makers may be reluctant to purchase complex instruments or quote prices for them. Derivatives may also expose the Fund to greater risk and increase its costs. Certain transactions in derivatives involve substantial leverage risk and may expose the Fund to potential losses that exceed the amount originally invested by the Fund.
	Hedging Risk — When a derivative is used as a hedge against a position that the Fund holds, any loss generated by the derivative generally should be substantially offset by gains on the hedged investment, and vice versa. While hedging can reduce or eliminate losses, it can also reduce or eliminate gains. Hedges are sometimes subject to imperfect matching between the derivative and the underlying security, and there can be no assurance that the Fund’s hedging transactions will be effective. The use of hedging may result in certain adverse tax consequences noted below.
	Tax Risk — The federal income tax treatment of a derivative may not be as favorable as a direct investment in an underlying asset and may adversely affect the timing, character and amount of income the Fund realizes from its investments. As a result, a larger portion of the Fund’s distributions may be treated as ordinary income rather than capital gains. In addition, certain derivatives are subject to mark-to-market or straddle provisions of the Internal Revenue Code of 1986, as amended (the “Internal Revenue Code”). If such provisions are applicable, there could be an increase (or decrease) in the amount of taxable dividends paid by the Fund. In addition, the tax treatment of certain derivatives, such as swaps, is unsettled and may be subject to future legislation, regulation or administrative pronouncements issued by the Internal Revenue Service (the “IRS”).
	Regulatory Risk — Derivative contracts, including, without limitation, swaps, currency forwards and non-deliverable forwards, are subject to regulation under the Dodd-Frank Wall Street Reform and Consumer Protection Act (the “Dodd-Frank Act”) in the United States and under comparable regimes in Europe, Asia and other non-U.S. jurisdictions. Under the Dodd-Frank Act, certain derivatives are subject to margin requirements and swap dealers are required to collect margin from the Fund with respect to such derivatives. Specifically, regulations are now in effect that require swap dealers to post and collect variation margin (comprised of specified liquid instruments and subject to a required haircut) in connection with trading of over the counter (“OTC”) swaps with the Fund. Shares of investment companies (other than certain money market funds) may not be posted as collateral under these regulations. Requirements for posting of initial margin in connection with OTC swaps will be phased-in through at least 2021. In addition, regulations adopted by global prudential regulators that are now in effect require certain bank-regulated counterparties and certain of their affiliates to include in certain financial contracts, including many derivatives contracts, terms that delay or restrict the rights of counterparties, such as the Fund, to terminate such contracts, foreclose upon collateral, exercise other default rights or restrict transfers of credit support in the event that the counterparty and/or its affiliates are subject to certain types of resolution or insolvency proceedings. The implementation of these requirements with respect to derivatives, as well as regulations under the Dodd-Frank Act regarding clearing, mandatory trading and margining of other derivatives, may increase the costs and risks to the Fund of trading in these instruments and, as a result, may affect returns to investors in the Fund.
	On October 28, 2020, the Securities and Exchange Commission adopted new regulations governing the use of derivatives by registered investment companies (“Rule 18f-4”). The Fund will be required to implement and comply

Table of Contents

	with Rule 18f-4 by August 19, 2022. Once implemented, Rule 18f-4 will impose limits on the amount of derivatives a fund can enter into, eliminate the asset segregation framework currently used by funds to comply with Section 18 of the Investment Company Act of 1940, as amended, treat derivatives as senior securities so that a failure to comply with the limits would result in a statutory violation and require funds whose use of derivatives is more than a limited specified exposure amount to establish and maintain a comprehensive derivatives risk management program and appoint a derivatives risk manager.
	In addition, other future regulatory developments may impact the Fund’s ability to invest or remain invested in certain derivatives. Legislation or regulation may also change the way in which the Fund itself is regulated. BlackRock cannot predict the effects of any new governmental regulation that may be implemented on the ability of the Fund to use swaps or any other financial derivative product, and there can be no assurance that any new governmental regulation will not adversely affect the Fund’s ability to achieve its investment objective.
	Risks Specific to Certain Derivatives Used by the Fund

Swaps — Swap agreements, including total return swaps that may be referred to as contracts for difference, are two-party contracts entered into for periods ranging from a few weeks to more than one year. In a standard “swap” transaction, two parties agree to exchange the returns (or differentials in rates of return) earned or realized on particular predetermined investments or instruments, which can be adjusted for an interest factor. Swap agreements involve the risk that the party with whom the Fund has entered into the swap will default on its obligation to pay the Fund and the risk that the Fund will not be able to meet its obligations to pay the other party to the agreement. Swap agreements may also involve the risk that there is an imperfect correlation between the return on the Fund’s obligation to its counterparty and the return on the referenced asset. In addition, swap agreements are subject to market and illiquidity risk, leverage risk and hedging risk.

Credit Default Swaps — Credit default swaps may have as reference obligations one or more securities that are not currently held by the Fund. The protection “buyer” may be obligated to pay the protection “seller” an up-front payment or a periodic stream of payments over the term of the contract, provided generally that no credit event on a reference obligation has occurred. Credit default swaps involve special risks in addition to those mentioned above because they are difficult to value, are highly susceptible to illiquid investments risk and credit risk, and generally pay a return to the party that has paid the premium only in the event of an actual default by the issuer of the underlying obligation (as opposed to a credit downgrade or other indication of financial difficulty).

Forward Foreign Currency Exchange Contracts — Forward foreign currency exchange transactions are OTC contracts to purchase or sell a specified amount of a specified currency or multinational currency unit at a price and future date set at the time of the contract. Forward foreign currency exchange contracts do not eliminate fluctuations in the value of non-U.S. securities but rather allow the Fund to establish a fixed rate of exchange for a future point in time. This strategy can have the effect of reducing returns and minimizing opportunities for gain.

Futures — Futures are standardized, exchange-traded contracts that obligate a purchaser to take delivery, and a seller to make delivery, of a specific amount of an asset at a specified future date at a specified price. The primary risks associated with the use of futures contracts and options are: (a) the imperfect correlation between the change in market value of the instruments held by the Fund and the price of the futures contract or option; (b) the possible lack of a liquid secondary market for a futures contract and the resulting inability to close a futures contract when desired; (c) losses caused by unanticipated market movements, which are potentially unlimited; (d) the investment adviser’s inability to predict correctly the direction of securities prices, interest rates, currency exchange rates and other economic factors; and (e) the possibility that the counterparty will default in the performance of its obligations.

Options — An option is an agreement that, for a premium payment or fee, gives the option holder (the purchaser) the right but not the obligation to buy (a “call option”) or sell (a “put option”) the underlying asset (or settle for cash in an amount based on an underlying asset, rate, or index) at a specified price (the “exercise price”) during a period of time or on a specified date. Investments in options are considered speculative. When the Fund purchases an option, it may lose the total premium paid for it if the price of the underlying security or other assets decreased, remained the same or failed to increase to a level at or beyond the exercise price (in the case of a call option) or increased, remained the same or failed to decrease to a level at or below the exercise price (in the case of a put option). If a put or call option purchased by the Fund were permitted to expire without being sold or exercised, its premium would represent a loss to the Fund. To the extent that the Fund writes or sells an option, if the decline or increase in the underlying asset is significantly below or above the exercise price of the written option, the Fund could experience a substantial loss.

Commodity-Linked Derivatives — The value of a commodity-linked derivative investment typically is based upon the price movements of a commodity, a commodity futures contract or commodity index, or some other readily measurable economic variable. The value of commodity-linked derivative instruments may be affected by changes

Table of Contents

in overall market movements, volatility of the underlying benchmark, changes in interest rates, or factors affecting a particular industry or commodity, such as drought, floods, weather, livestock disease, embargoes, tariffs and international economic, political and regulatory developments. The value of commodity-linked derivatives will rise or fall in response to changes in the underlying commodity or related index. Investments in commodity-linked derivatives may be subject to greater volatility than non-derivative based investments. A highly liquid secondary market may not exist for certain commodity-linked derivatives, and there can be no assurance that one will develop.

Commodity-linked derivatives also may be subject to credit and interest rate risks that in general affect the values of fixed-income securities. Therefore, at maturity, the Fund may receive more or less principal than it originally invested. The Fund might receive interest payments that are more or less than the stated coupon interest payments.

In connection with the Fund’s direct and indirect investments in commodity-linked derivatives, the Fund will attempt to manage its counterparty exposure so as to limit its exposure to any one counterparty. However, due to the limited number of entities that may serve as counterparties (and which the Fund believes are creditworthy) at any one time the Fund may enter into swap agreements with a limited number of counterparties and may invest in commodity-linked notes issued by a limited number of issuers that will act as counterparties, which may increase the Fund’s exposure to counterparty credit risk. There can be no assurance that the Fund will be able to limit exposure to any one counterparty at all times.

Commodity-Linked Notes — Commodity-linked notes involve substantial risks, including the risk of loss of a significant portion of their principal value. In addition to commodity risk and general derivatives risk, they may be subject to additional special risks, such as risk of loss of interest and principal, lack of secondary market and risk of greater volatility, that do not affect traditional equity and debt securities.

■	Dollar Rolls Risk — A dollar roll transaction involves a sale by the Fund of a mortgage-backed, U.S. Treasury or other security (as permitted by the Fund’s investment strategies) concurrently with an agreement by the Fund to repurchase a similar security at a later date at an agreed-upon price. The market value of the securities the Fund is required to purchase may decline below the agreed upon repurchase price of those securities. If the broker/dealer to whom the Fund sells securities becomes insolvent, the Fund’s right to purchase or repurchase securities may be restricted. Successful use of dollar rolls may depend upon the adviser’s ability to correctly predict interest rates and prepayments, depending on the underlying security. There is no assurance that dollar rolls can be successfully employed.
■	Emerging Markets Risk — The risks of foreign investments are usually much greater for emerging markets. Investments in emerging markets may be considered speculative. Emerging markets may include those in countries considered emerging or developing by the World Bank, the International Finance Corporation or the United Nations. Emerging markets are riskier than more developed markets because they tend to develop unevenly and may never fully develop. They are more likely to experience hyperinflation and currency devaluations, which adversely affect returns to U.S. investors. In addition, many emerging markets have far lower trading volumes and less liquidity than developed markets. Since these markets are often small, they may be more likely to suffer sharp and frequent price changes or long-term price depression because of adverse publicity, investor perceptions or the actions of a few large investors. In addition, traditional measures of investment value used in the United States, such as price to earnings ratios, may not apply to certain small markets. Also, there may be less publicly available information about issuers in emerging markets than would be available about issuers in more developed capital markets, and such issuers may not be subject to accounting, auditing and financial reporting standards and requirements comparable to those to which U.S. companies are subject.
	Many emerging markets have histories of political instability and abrupt changes in policies. As a result, their governments are more likely to take actions that are hostile or detrimental to private enterprise or foreign investment than those of more developed countries, including expropriation of assets, confiscatory taxation, high rates of inflation or unfavorable diplomatic developments. In the past, governments of such nations have expropriated substantial amounts of private property, and most claims of the property owners have never been fully settled. There is no assurance that such expropriations will not reoccur. In such an event, it is possible that the Fund could lose the entire value of its investments in the affected market. Some countries have pervasive corruption and crime that may hinder investments. Certain emerging markets may also face other significant internal or external risks, including the risk of war, and ethnic, religious and racial conflicts. In addition, governments in many emerging market countries participate to a significant degree in their economies and securities markets, which may impair investment and economic growth. National policies that may limit the Fund’s investment opportunities include restrictions on investment in issuers or industries deemed sensitive to national interests.

Table of Contents

	Emerging markets may also have differing legal systems and the existence or possible imposition of exchange controls, custodial restrictions or other foreign or U.S. governmental laws or restrictions applicable to such investments. Sometimes, they may lack or be in the relatively early development of legal structures governing private and foreign investments and private property. Many emerging markets do not have income tax treaties with the United States, and as a result, investments by the Fund may be subject to higher withholding taxes in such countries. In addition, some countries with emerging markets may impose differential capital gains taxes on foreign investors.
	Practices in relation to settlement of securities transactions in emerging markets involve higher risks than those in developed markets, in part because the Fund will need to use brokers and counterparties that are less well capitalized, and custody and registration of assets in some countries may be unreliable. The possibility of fraud, negligence, undue influence being exerted by the issuer or refusal to recognize ownership exists in some emerging markets, and, along with other factors, could result in ownership registration being completely lost. The Fund would absorb any loss resulting from such registration problems and may have no successful claim for compensation. In addition, communications between the United States and emerging market countries may be unreliable, increasing the risk of delayed settlements or losses of security certificates.
■	Foreign Securities Risk — Securities traded in foreign markets have often (though not always) performed differently from securities traded in the United States. However, such investments often involve special risks not present in U.S. investments that can increase the chances that the Fund will lose money. In particular, the Fund is subject to the risk that because there may be fewer investors on foreign exchanges and a smaller number of securities traded each day, it may be more difficult for the Fund to buy and sell securities on those exchanges. In addition, prices of foreign securities may go up and down more than prices of securities traded in the United States.
	Certain Risks of Holding Fund Assets Outside the United States — The Fund generally holds its foreign securities and cash in foreign banks and securities depositories. Some foreign banks and securities depositories may be recently organized or new to the foreign custody business. In addition, there may be limited or no regulatory oversight of their operations. Also, the laws of certain countries limit the Fund’s ability to recover its assets if a foreign bank, depository or issuer of a security, or any of their agents, goes bankrupt. In addition, it is often more expensive for the Fund to buy, sell and hold securities in certain foreign markets than in the United States. The increased expense of investing in foreign markets reduces the amount the Fund can earn on its investments and typically results in a higher operating expense ratio for the Fund than for investment companies invested only in the United States.
	Currency Risk — Securities and other instruments in which the Fund invests may be denominated or quoted in currencies other than the U.S. dollar. For this reason, changes in foreign currency exchange rates can affect the value of the Fund’s portfolio.
	Generally, when the U.S. dollar rises in value against a foreign currency, a security denominated in that currency loses value because the currency is worth fewer U.S. dollars. Conversely, when the U.S. dollar decreases in value against a foreign currency, a security denominated in that currency gains value because the currency is worth more U.S. dollars. This risk, generally known as “currency risk,” means that a strong U.S. dollar will reduce returns for U.S. investors while a weak U.S. dollar will increase those returns.
	Foreign Economy Risk — The economies of certain foreign markets may not compare favorably with the economy of the United States with respect to such issues as growth of gross national product, reinvestment of capital, resources and balance of payments position. Certain foreign economies may rely heavily on particular industries or foreign capital and are more vulnerable to diplomatic developments, the imposition of economic sanctions against a particular country or countries, changes in international trading patterns, trade barriers and other protectionist or retaliatory measures. Investments in foreign markets may also be adversely affected by governmental actions such as the imposition of capital controls, nationalization of companies or industries, expropriation of assets or the imposition of punitive taxes. In addition, the governments of certain countries may prohibit or impose substantial restrictions on foreign investments in their capital markets or in certain industries. Any of these actions could severely affect securities prices or impair the Fund’s ability to purchase or sell foreign securities or transfer the Fund’s assets or income back into the United States, or otherwise adversely affect the Fund’s operations.
	Other potential foreign market risks include foreign exchange controls, difficulties in pricing securities, defaults on foreign government securities, difficulties in enforcing legal judgments in foreign courts and political and social instability. Diplomatic and political developments, including rapid and adverse political changes, social instability, regional conflicts, terrorism and war, could affect the economies, industries and securities and currency markets, and the value of the Fund’s investments, in non-U.S. countries. These factors are extremely difficult, if not impossible, to predict and take into account with respect to the Fund’s investments.
	Governmental Supervision and Regulation/Accounting Standards — Many foreign governments do not supervise and regulate stock exchanges, brokers and the sale of securities to the same extent as such regulations exist in

Table of Contents

	the United States. They also may not have laws to protect investors that are comparable to U.S. securities laws. For example, some foreign countries may have no laws or rules against insider trading. Insider trading occurs when a person buys or sells a company’s securities based on material non-public information about that company. In addition, some countries may have legal systems that may make it difficult for the Fund to vote proxies, exercise shareholder rights, and pursue legal remedies with respect to its foreign investments. Accounting standards in other countries are not necessarily the same as in the United States. If the accounting standards in another country do not require as much detail as U.S. accounting standards, it may be harder for Fund management to completely and accurately determine a company’s financial condition.
	Settlement Risk — Settlement and clearance procedures in certain foreign markets differ significantly from those in the United States. Foreign settlement and clearance procedures and trade regulations also may involve certain risks (such as delays in payment for or delivery of securities) not typically associated with the settlement of U.S. investments.
	At times, settlements in certain foreign countries have not kept pace with the number of securities transactions. These problems may make it difficult for the Fund to carry out transactions. If the Fund cannot settle or is delayed in settling a purchase of securities, it may miss attractive investment opportunities and certain of its assets may be uninvested with no return earned thereon for some period. If the Fund cannot settle or is delayed in settling a sale of securities, it may lose money if the value of the security then declines or, if it has contracted to sell the security to another party, the Fund could be liable for any losses incurred.
	Withholding Tax Reclaims Risk -- The Fund may file claims to recover foreign withholding taxes on dividend and interest income (if any) received from issuers in certain countries and capital gains on the disposition of stocks or securities where such withholding tax reclaim is possible. Whether or when the Fund will receive a withholding tax refund is within the control of the tax authorities in such countries. Where the Fund expects to recover withholding taxes, the net asset value of the Fund generally includes accruals for such tax refunds. The Fund regularly evaluates the probability of recovery. If the likelihood of recovery materially decreases, due to, for example, a change in tax regulation or approach in the foreign country, accruals in the Fund’s net asset value for such refunds may be written down partially or in full, which will adversely affect the Fund’s net asset value. Shareholders in the Fund at the time an accrual is written down will bear the impact of the resulting reduction in net asset value regardless of whether they were shareholders during the accrual period. Conversely, if the Fund receives a tax refund that has not been previously accrued, shareholders in the Fund at the time of the successful recovery will benefit from the resulting increase in the Fund’s net asset value. Shareholders who sold their shares prior to such time will not benefit from such increase in the Fund’s net asset value.
	European Economic Risk — The European financial markets have recently experienced volatility and adverse trends due to concerns about economic downturns in, or rising government debt levels of, several European countries. These events may spread to other countries in Europe. These events may affect the value and liquidity of certain of the Fund’s investments.
	Responses to the financial problems by European governments, central banks and others, including austerity measures and reforms, may not work, may result in social unrest and may limit future growth and economic recovery or have other unintended consequences. Further defaults or restructurings by governments and others of their debt could have additional adverse effects on economies, financial markets and asset valuations around the world. In addition, the United Kingdom has voted to withdraw from the European Union, and one or more other countries may withdraw from the European Union and/or abandon the Euro, the common currency of the European Union. The impact of these actions, especially if they occur in a disorderly fashion, is not clear but could be significant and far reaching.
■	High Portfolio Turnover Risk — The Fund may engage in active and frequent trading of its portfolio securities. High portfolio turnover (more than 100%) may result in increased transaction costs to the Fund, including brokerage commissions, dealer mark-ups and other transaction costs on the sale of the securities and on reinvestment in other securities. The sale of Fund portfolio securities may result in the realization and/or distribution to shareholders of higher capital gains or losses as compared to a fund with less active trading policies. These effects of higher than normal portfolio turnover may adversely affect Fund performance. In addition, investment in mortgage dollar rolls and participation in to-be-announced (“TBA”) transactions may significantly increase the Fund’s portfolio turnover rate. A TBA transaction is a method of trading mortgage-backed securities where the buyer and seller agree upon general trade parameters such as agency, settlement date, par amount, and price at the time the contract is entered into but the mortgage-backed securities are delivered in the future, generally 30 days later.
■	Junk Bonds Risk — Although junk bonds generally pay higher rates of interest than investment grade bonds, junk bonds are high risk investments that are considered speculative and may cause income and principal losses for the Fund. The major risks of junk bond investments include:

Table of Contents

■	Junk bonds may be issued by less creditworthy issuers. Issuers of junk bonds may have a larger amount of outstanding debt relative to their assets than issuers of investment grade bonds. In the event of an issuer’s bankruptcy, claims of other creditors may have priority over the claims of junk bond holders, leaving few or no assets available to repay junk bond holders.
■	Prices of junk bonds are subject to extreme price fluctuations. Adverse changes in an issuer’s industry and general economic conditions may have a greater impact on the prices of junk bonds than on other higher rated fixed-income securities.
■	Issuers of junk bonds may be unable to meet their interest or principal payment obligations because of an economic downturn, specific issuer developments, or the unavailability of additional financing.
■	Junk bonds frequently have redemption features that permit an issuer to repurchase the security from the Fund before it matures. If the issuer redeems junk bonds, the Fund may have to invest the proceeds in bonds with lower yields and may lose income.
■	Junk bonds may be less liquid than higher rated fixed-income securities, even under normal economic conditions. There are fewer dealers in the junk bond market, and there may be significant differences in the prices quoted for junk bonds by the dealers. Because they are less liquid than higher rated fixed-income securities, judgment may play a greater role in valuing junk bonds than is the case with securities trading in a more liquid market.
■	The Fund may incur expenses to the extent necessary to seek recovery upon default or to negotiate new terms with a defaulting issuer.

The credit rating of a high yield security does not necessarily address its market value risk. Ratings and market value may change from time to time, positively or negatively, to reflect new developments regarding the issuer.

■	Leverage Risk — Some transactions may give rise to a form of economic leverage. These transactions may include, among others, derivatives, and may expose the Fund to greater risk and increase its costs. As an open-end investment company registered with the Securities and Exchange Commission (the “SEC”), the Fund is subject to the federal securities laws, including the Investment Company Act, the rules thereunder, and various SEC and SEC staff interpretive positions. In accordance with these laws, rules and positions, the Fund must “set aside” liquid assets (often referred to as “asset segregation”), or engage in other SEC- or staff-approved measures, to “cover” open positions with respect to certain kinds of instruments. The use of leverage may cause the Fund to liquidate portfolio positions when it may not be advantageous to do so to satisfy its obligations or to meet any required asset segregation requirements. Increases and decreases in the value of the Fund’s portfolio will be magnified when the Fund uses leverage.
■	Market Risk and Selection Risk — Market risk is the risk that one or more markets in which the Fund invests will go down in value, including the possibility that the markets will go down sharply and unpredictably. The value of a security or other asset may decline due to changes in general market conditions, economic trends or events that are not specifically related to the issuer of the security or other asset, or factors that affect a particular issuer or issuers, exchange, country, group of countries, region, market, industry, group of industries, sector or asset class. Local, regional or global events such as war, acts of terrorism, the spread of infectious illness or other public health issues like pandemics or epidemics, recessions, or other events could have a significant impact on the Fund and its investments. Selection risk is the risk that the securities selected by Fund management will underperform the markets, the relevant indices or the securities selected by other funds with similar investment objectives and investment strategies. This means you may lose money.
	A recent outbreak of an infectious coronavirus has developed into a global pandemic that has resulted in numerous disruptions in the market and has had significant economic impact leaving general concern and uncertainty. The impact of this coronavirus, and other epidemics and pandemics that may arise in the future, could affect the economies of many nations, individual companies and the market in general ways that cannot necessarily be foreseen at the present time.
■	Mortgage- and Asset-Backed Securities Risks — Mortgage-backed securities (residential and commercial) and asset-backed securities represent interests in “pools” of mortgages or other assets, including consumer loans or receivables held in trust. Although asset-backed and commercial mortgage-backed securities (“CMBS”) generally experience less prepayment than residential mortgage-backed securities, mortgage-backed and asset-backed securities, like traditional fixed-income securities, are subject to credit, interest rate, prepayment and extension risks.
	Small movements in interest rates (both increases and decreases) may quickly and significantly reduce the value of certain mortgage-backed securities. The Fund’s investments in asset-backed securities are subject to risks similar to those associated with mortgage-related securities, as well as additional risks associated with the nature of the assets and the servicing of those assets. These securities also are subject to the risk of default on the underlying mortgages or assets, particularly during periods of economic downturn. Certain CMBS are issued in several classes

Table of Contents

	with different levels of yield and credit protection. The Fund’s investments in CMBS with several classes may be in the lower classes that have greater risks than the higher classes, including greater interest rate, credit and prepayment risks.
	Mortgage-backed securities may be either pass-through securities or collateralized mortgage obligations (“CMOs”). Pass-through securities represent a right to receive principal and interest payments collected on a pool of mortgages, which are passed through to security holders. CMOs are created by dividing the principal and interest payments collected on a pool of mortgages into several revenue streams (“tranches”) with different priority rights to portions of the underlying mortgage payments. Certain CMO tranches may represent a right to receive interest only (“IOs”), principal only (“POs”) or an amount that remains after floating-rate tranches are paid (an “inverse floater”). These securities are frequently referred to as “mortgage derivatives” and may be extremely sensitive to changes in interest rates. Interest rates on inverse floaters, for example, vary inversely with a short-term floating rate (which may be reset periodically). Interest rates on inverse floaters will decrease when short-term rates increase, and will increase when short-term rates decrease. These securities have the effect of providing a degree of investment leverage. In response to changes in market interest rates or other market conditions, the value of an inverse floater may increase or decrease at a multiple of the increase or decrease in the value of the underlying securities. If the Fund invests in CMO tranches (including CMO tranches issued by government agencies) and interest rates move in a manner not anticipated by Fund management, it is possible that the Fund could lose all or substantially all of its investment. Certain mortgage-backed securities in which the Fund may invest may also provide a degree of investment leverage, which could cause the Fund to lose all or substantially all of its investment.
	The mortgage market in the United States has experienced difficulties that may adversely affect the performance and market value of certain of the Fund’s mortgage-related investments. Delinquencies and losses on mortgage loans (including subprime and second-lien mortgage loans) generally have increased and may continue to increase, and a decline in or flattening of real estate values (as has been experienced and may continue to be experienced in many housing markets) may exacerbate such delinquencies and losses. Also, a number of mortgage loan originators have experienced serious financial difficulties or bankruptcy. Reduced investor demand for mortgage loans and mortgage-related securities and increased investor yield requirements have caused limited liquidity in the secondary market for mortgage-related securities, which can adversely affect the market value of mortgage-related securities. It is possible that such limited liquidity in such secondary markets could continue or worsen.
	Asset-backed securities entail certain risks not presented by mortgage-backed securities, including the risk that in certain states it may be difficult to perfect the liens securing the collateral backing certain asset-backed securities. In addition, certain asset-backed securities are based on loans that are unsecured, which means that there is no collateral to seize if the underlying borrower defaults.
■	Preferred Securities Risk — Preferred securities may pay fixed or adjustable rates of return. Preferred securities are subject to issuer-specific and market risks applicable generally to equity securities. In addition, a company’s preferred securities generally pay dividends only after the company makes required payments to holders of its bonds and other debt. For this reason, the value of preferred securities will usually react more strongly than bonds and other debt to actual or perceived changes in the company’s financial condition or prospects. Preferred securities of smaller companies may be more vulnerable to adverse developments than preferred securities of larger companies.
■	Reverse Repurchase Agreements Risk — Reverse repurchase agreements involve the sale of securities held by the Fund with an agreement to repurchase the securities at an agreed-upon price, date and interest payment. Reverse repurchase agreements involve the risk that the other party may fail to return the securities in a timely manner or at all. The Fund could lose money if it is unable to recover the securities and the value of the collateral held by the Fund, including the value of the investments made with cash collateral, is less than the value of the securities. These events could also trigger adverse tax consequences for the Fund. In addition, reverse repurchase agreements involve the risk that the interest income earned in the investment of the proceeds will be less than the interest expense.
■	Sovereign Debt Risk — Sovereign debt instruments are subject to the risk that a governmental entity may delay or refuse to pay interest or repay principal on its sovereign debt, due, for example, to cash flow problems, insufficient foreign currency reserves, political considerations, the relative size of the governmental entity’s debt position in relation to the economy or the failure to put in place economic reforms required by the International Monetary Fund or other multilateral agencies. If a governmental entity defaults, it may ask for more time in which to pay or for further loans. There is no legal process for collecting sovereign debt that a government does not pay nor are there bankruptcy proceedings through which all or part of the sovereign debt that a governmental entity has not repaid may be collected.
■	Structured Notes Risk — Structured notes and other related instruments purchased by the Fund are generally privately negotiated debt obligations where the principal and/or interest is determined by reference to the

Table of Contents

	performance of a specific asset, benchmark asset, market or interest rate (“reference measure”). The interest rate or the principal amount payable upon maturity or redemption may increase or decrease, depending upon changes in the value of the reference measure. The terms of a structured note may provide that, in certain circumstances, no principal is due at maturity and, therefore, may result in a loss of invested capital by the Fund. The interest and/or principal payments that may be made on a structured product may vary widely, depending on a variety of factors, including the volatility of the reference measure.
	Structured notes may be positively or negatively indexed, so the appreciation of the reference measure may produce an increase or a decrease in the interest rate or the value of the principal at maturity. The rate of return on structured notes may be determined by applying a multiplier to the performance or differential performance of reference measures. Application of a multiplier involves leverage that will serve to magnify the potential for gain and the risk of loss.
	The purchase of structured notes exposes the Fund to the credit risk of the issuer of the structured product. Structured notes may also be more volatile, less liquid, and more difficult to price accurately than less complex securities and instruments or more traditional debt securities.
■	U.S. Government Issuer Risk — Treasury obligations may differ in their interest rates, maturities, times of issuance and other characteristics. Obligations of U.S. Government agencies and authorities are supported by varying degrees of credit but generally are not backed by the full faith and credit of the U.S. Government. No assurance can be given that the U.S. Government will provide financial support to its agencies and authorities if it is not obligated by law to do so.

The Fund may also be subject to certain other non-principal risks associated with its investments and investment strategies, including:

■	Borrowing Risk — Borrowing may exaggerate changes in the net asset value of Fund shares and in the return on the Fund’s portfolio. Borrowing will cost the Fund interest expense and other fees. The costs of borrowing may reduce the Fund’s return. Borrowing may cause the Fund to liquidate positions when it may not be advantageous to do so to satisfy its obligations.
■	Corporate Loans Risk — Commercial banks and other financial institutions or institutional investors make corporate loans to companies that need capital to grow or restructure. Borrowers generally pay interest on corporate loans at rates that change in response to changes in market interest rates such as the London Interbank Offered Rate (“LIBOR”) or the prime rates of U.S. banks. As a result, the value of corporate loan investments is generally less exposed to the adverse effects of shifts in market interest rates than investments that pay a fixed rate of interest. However, because the trading market for certain corporate loans may be less developed than the secondary market for bonds and notes, the Fund may experience difficulties in selling its corporate loans. Transactions in corporate loans may settle on a delayed basis. As a result, the proceeds from the sale of corporate loans may not be readily available to make additional investments or to meet the Fund’s redemption obligations. To the extent the extended settlement process gives rise to short-term liquidity needs, the Fund may hold additional cash, sell investments or temporarily borrow from banks and other lenders. Leading financial institutions often act as agent for a broader group of lenders, generally referred to as a syndicate. The syndicate’s agent arranges the corporate loans, holds collateral and accepts payments of principal and interest. If the agent develops financial problems, the Fund may not recover its investment or recovery may be delayed. By investing in a corporate loan, the Fund may become a member of the syndicate.
	The market for corporate loans may be subject to irregular trading activity and wide bid/ask spreads.
	The corporate loans in which the Fund invests are subject to the risk of loss of principal and income. Although borrowers frequently provide collateral to secure repayment of these obligations they do not always do so. If they do provide collateral, the value of the collateral may not completely cover the borrower’s obligations at the time of a default. If a borrower files for protection from its creditors under the U.S. bankruptcy laws, these laws may limit the Fund’s rights to its collateral. In addition, the value of collateral may erode during a bankruptcy case. In the event of a bankruptcy, the holder of a corporate loan may not recover its principal, may experience a long delay in recovering its investment and may not receive interest during the delay.
■	Cyber Security Risk — Failures or breaches of the electronic systems of the Fund, the Fund’s adviser, distributor, and other service providers, or the issuers of securities in which the Fund invests have the ability to cause disruptions and negatively impact the Fund’s business operations, potentially resulting in financial losses to the Fund and its shareholders. While the Fund has established business continuity plans and risk management systems seeking to address system breaches or failures, there are inherent limitations in such plans and systems. Furthermore, the Fund cannot control the cyber security plans and systems of the Fund’s service providers or issuers of securities in which the Fund invests.

Table of Contents

■	Expense Risk — Fund expenses are subject to a variety of factors, including fluctuations in the Fund’s net assets. Accordingly, actual expenses may be greater or less than those indicated. For example, to the extent that the Fund’s net assets decrease due to market declines or redemptions, the Fund’s expenses will increase as a percentage of Fund net assets. During periods of high market volatility, these increases in the Fund’s expense ratio could be significant.
■	Illiquid Investments Risk — The Fund’s illiquid investments may reduce the returns of the Fund because it may be difficult to sell the illiquid investments at an advantageous time or price. An investment may be illiquid due to, among other things, the reduced number and capacity of traditional market participants to make a market in fixed-income securities or the lack of an active trading market. To the extent that the Fund’s principal investment strategies involve derivatives or securities with substantial market and/or credit risk, the Fund will tend to have the greatest exposure to the risks associated with illiquid investments. Liquid investments may become illiquid after purchase by the Fund, particularly during periods of market turmoil. Illiquid investments may be harder to value, especially in changing markets, and if the Fund is forced to sell these investments to meet redemption requests or for other cash needs, the Fund may suffer a loss. This may be magnified in a rising interest rate environment or other circumstances where investor redemptions from fixed-income mutual funds may be higher than normal. In addition, when there is illiquidity in the market for certain securities, the Fund, due to limitations on illiquid investments, may be subject to purchase and sale restrictions.
■	Indexed and Inverse Securities Risk — Indexed and inverse securities provide a potential return based on a particular index of value or interest rates. The Fund’s return on these securities will be subject to risk with respect to the value of the particular index. These securities are subject to leverage risk and correlation risk. Certain indexed and inverse securities have greater sensitivity to changes in interest rates or index levels than other securities, and the Fund’s investment in such instruments may decline significantly in value if interest rates or index levels move in a way Fund management does not anticipate.
■	Investment in Other Investment Companies Risk — As with other investments, investments in other investment companies, including ETFs, are subject to market and selection risk. In addition, if the Fund acquires shares of investment companies, including ones affiliated with the Fund, shareholders bear both their proportionate share of expenses in the Fund (including management and advisory fees) and, indirectly, the expenses of the investment companies (to the extent not offset by BlackRock through waivers). To the extent the Fund is held by an affiliated fund, the ability of the Fund itself to hold other investment companies may be limited.
■	LIBOR Risk — The Fund may be exposed to financial instruments that are tied to the London Interbank Offered Rate (“LIBOR”) to determine payment obligations, financing terms, hedging strategies or investment value. The Fund’s investments may pay interest at floating rates based on LIBOR or may be subject to interest caps or floors based on LIBOR. The Fund may also obtain financing at floating rates based on LIBOR. Derivative instruments utilized by the Fund may also reference LIBOR.
	In 2017, the head of the United Kingdom’s Financial Conduct Authority announced a desire to phase out the use of LIBOR by the end of 2021, and it is expected that LIBOR will cease to be published after that time. The Fund may have investments linked to other interbank offered rates, such as the Euro Overnight Index Average (“EONIA”), which may also cease to be published. Various financial industry groups have begun planning for the transition away from LIBOR, but there are challenges to converting certain securities and transactions to a new reference rate (e.g., the Secured Overnight Financing Rate (“SOFR”), which is intended to replace the U.S. dollar LIBOR).
	Neither the effect of the LIBOR transition process nor its ultimate success can yet be known. The transition process might lead to increased volatility and illiquidity in markets for, and reduce the effectiveness of new hedges placed against, instruments whose terms currently include LIBOR. While some existing LIBOR-based instruments may contemplate a scenario where LIBOR is no longer available by providing for an alternative rate-setting methodology, there may be significant uncertainty regarding the effectiveness of any such alternative methodologies to replicate LIBOR. Not all existing LIBOR-based instruments may have alternative rate-setting provisions and there remains uncertainty regarding the willingness and ability of issuers to add alternative rate-setting provisions in certain existing instruments. In addition, a liquid market for newly-issued instruments that use a reference rate other than LIBOR still may be developing. There may also be challenges for the Fund to enter into hedging transactions against such newly-issued instruments until a market for such hedging transactions develops. All of the aforementioned may adversely affect the Fund’s performance or net asset value.
■	Repurchase Agreements and Purchase and Sale Contracts Risk — If the other party to a repurchase agreement or purchase and sale contract defaults on its obligation under the agreement, the Fund may suffer delays and incur costs or lose money in exercising its rights under the agreement. If the seller fails to repurchase the security in either situation and the market value of the security declines, the Fund may lose money.
■	Restricted Securities Risk — Limitations on the resale of restricted securities may have an adverse effect on their marketability, and may prevent the Fund from disposing of them promptly at advantageous prices. Restricted

Table of Contents

	securities may not be listed on an exchange and may have no active trading market. In order to sell such securities, the Fund may have to bear the expense of registering the securities for resale and the risk of substantial delays in effecting the registration. Other transaction costs may be higher for restricted securities than unrestricted securities. Restricted securities may be difficult to value because market quotations may not be readily available, and the securities may have significant volatility. Also, the Fund may get only limited information about the issuer of a given restricted security, and therefore may be less able to predict a loss. Certain restricted securities may involve a high degree of business and financial risk and may result in substantial losses to the Fund.
■	Securities Lending Risk — Securities lending involves the risk that the borrower may fail to return the securities in a timely manner or at all. As a result, the Fund may lose money and there may be a delay in recovering the loaned securities. The Fund could also lose money if it does not recover the securities and/or the value of the collateral falls, including the value of investments made with cash collateral. These events could trigger adverse tax consequences for the Fund.
■	Standby Commitment Agreements Risk — Standby commitment agreements involve the risk that the security the Fund buys will lose value prior to its delivery to the Fund and will no longer be worth what the Fund has agreed to pay for it. These agreements also involve the risk that if the security goes up in value, the counterparty will decide not to issue the security. In this case, the Fund loses both the investment opportunity for the assets it set aside to pay for the security and any gain in the security’s price.
■	Valuation Risk — The price the Fund could receive upon the sale of any particular portfolio investment may differ from the Fund’s valuation of the investment, particularly for securities that trade in thin or volatile markets or that are valued using a fair valuation methodology or a price provided by an independent pricing service. As a result, the price received upon the sale of an investment may be less than the value ascribed by the Fund, and the Fund could realize a greater than expected loss or lesser than expected gain upon the sale of the investment. Pricing services that value fixed-income securities generally utilize a range of market-based and security-specific inputs and assumptions, as well as considerations about general market conditions, to establish a price. Pricing services generally value fixed-income securities assuming orderly transactions of an institutional round lot size, but may be held or transactions may be conducted in such securities in smaller, odd lot sizes. Odd lots may trade at lower prices than institutional round lots. The Fund’s ability to value its investments may also be impacted by technological issues and/or errors by pricing services or other third-party service providers.
■	When-Issued and Delayed Delivery Securities and Forward Commitments Risk — When-issued and delayed delivery securities and forward commitments involve the risk that the security the Fund buys will lose value prior to its delivery. There also is the risk that the security will not be issued or that the other party to the transaction will not meet its obligation. If this occurs, the Fund may lose both the investment opportunity for the assets it set aside to pay for the security and any gain in the security’s price.

Table of Contents

Account Information

Details About the Share Class

The Fund currently offers multiple share classes (Class K Shares in this prospectus), each with its own sales charge and expense structure, allowing you to invest in the way that best suits your needs. Each share class represents an ownership interest in the same investment portfolio of the Fund. When you choose your class of shares, you should consider the size of your investment and how long you plan to hold your shares. Only certain investors are eligible to buy Class K Shares. Either your financial professional or your selected securities dealer, broker, investment adviser, service provider or industry professional (including BlackRock and its affiliates) (each a “Financial Intermediary”) can help you determine whether you are eligible to buy Class K Shares.

The Fund’s shares are distributed by BlackRock Investments, LLC (the “Distributor”), an affiliate of BlackRock.

The table below summarizes key features of Class K Shares of the Fund.

Class K Shares at a Glance


Availability	Available only to (i) certain employee benefit plans, such as health savings accounts, and certain employer-sponsored retirement plans (not including SEP IRAs, SIMPLE IRAs and SARSEPs) (collectively “Employer-Sponsored Retirement Plans”), (ii) collective trust funds, investment companies and other pooled investment vehicles, each of which may purchase shares of the Fund through a Financial Intermediary that has entered into an agreement with the Distributor to purchase such shares, (iii) “Institutional Investors,” which include, but are not limited to, endowments, foundations, family offices, banks and bank trusts, local, city, and state governmental institutions, corporations and insurance company separate accounts, each of which may purchase shares of the Fund through a Financial Intermediary that has entered into an agreement with the Distributor to purchase such shares, (iv) clients of private banks that purchase shares of the Fund through a Financial Intermediary that has entered into an agreement with the Distributor to sell such shares, (v) fee-based advisory platforms of a Financial Intermediary that (a) has specifically acknowledged in a written agreement with the Distributor and/or its affiliate(s) that the Financial Intermediary shall offer such shares to fee-based advisory clients through an omnibus account held at the Fund or (b) transacts in the Fund’s shares through another intermediary that has executed such an agreement and (vi) any other investors who met the eligibility criteria for BlackRock Shares or Class K Shares prior to August 15, 2016 and have continually held Class K Shares of the Fund in the same account since August 15, 2016.
Minimum Investment	$5 million minimum initial investment for Institutional Investors. There is no minimum initial investment requirement for any Employer-Sponsored Retirement Plans or any other eligible investors other than Institutional Investors. There is no minimum investment amount for additional purchases.
Initial Sales Charge?	No. Entire purchase price is invested in shares of the Fund.
Deferred Sales Charge?	No.
Distribution and Service (12b-1) Fees?	No.
Redemption Fees?	No.

The Fund reserves the right to modify or waive the above-stated policies at any time.

When Class K Shares are purchased through a customer’s account in an Employer-Sponsored Retirement Plan through procedures established by the Employer-Sponsored Retirement Plan, confirmation of share purchases and redemptions will be sent to the Employer-Sponsored Retirement Plan. A customer’s ownership of shares will be recorded by the Employer-Sponsored Retirement Plan and reflected in the account statements provided by the Employer-Sponsored Retirement Plan to its participants.

Table of Contents

If you purchased your shares through an Employer-Sponsored Retirement Plan and you transfer your investment from an Employer-Sponsored Retirement Plan to a type of account, such as an individual retirement account, that is not an eligible Class K Share investor in the Fund, you must liquidate your investment in Class K Shares of the Fund and purchase a share class of the Fund or another fund advised by BlackRock or its affiliates that is available for purchase by that type of account.

For investors not purchasing shares through an Employer-Sponsored Retirement Plan, please see below for information on how to buy, sell, exchange and transfer shares.

Right of Accumulation

Investors have a “right of accumulation” under which any of the following may be combined with the amount of the current purchase in determining whether an investor qualifies for a breakpoint and a reduced front-end sales charge:

i.	The current value of an investor’s existing Investor A and A1, Investor C, Investor P, Institutional, Class K and Premier Shares in most mutual funds sponsored and advised by BlackRock or its affiliates (“BlackRock Funds”),
ii.	The current value of an investor’s existing shares of certain unlisted closed-end management investment companies sponsored and advised by BlackRock or its affiliates and
iii.	The investment in the BlackRock CollegeAdvantage 529 Program by the investor or by or on behalf of the investor’s spouse and children.

Financial Intermediaries may value current holdings of their customers differently for purposes of determining whether an investor qualifies for a breakpoint and a reduced front-end sales charge, although customers of the same Financial Intermediary will be treated similarly. In order to use this right, the investor must alert BlackRock to the existence of any previously purchased shares.

How to Buy, Sell, Exchange and Transfer Shares

The chart on the following pages summarizes how to buy, sell, exchange and transfer shares through your Financial Intermediary. If you are not purchasing shares through an Employer-Sponsored Retirement Plan, you may also buy, sell, exchange and transfer shares through BlackRock if your account is held directly with BlackRock. To learn more about buying, selling, exchanging or transferring shares through BlackRock, call (800) 537-4942. Because the selection of a mutual fund involves many considerations, your Financial Intermediary may help you with this decision.

With certain limited exceptions, the Fund is generally available only to investors residing in the United States and may not be distributed by a foreign Financial Intermediary. Under this policy, in order to accept new accounts or additional investments (including by way of exchange from another BlackRock Fund) into existing accounts, the Fund generally requires that (i) a shareholder that is a natural person be a U.S. citizen or resident alien, in each case residing within the United States or a U.S. territory (including APO/FPO/DPO addresses), and have a valid U.S. taxpayer identification number, and (ii) a Financial Intermediary or a shareholder that is an entity be domiciled in the United States and have a valid U.S. taxpayer identification number or be domiciled in a U.S. territory and have a valid U.S. taxpayer identification number or IRS Form W-8. Any existing account that is updated to reflect a non-U.S. address will also be restricted from making additional investments.

The Fund may reject any purchase order, modify or waive the minimum initial or subsequent investment requirements for any shareholders and suspend and resume the sale of any share class of the Fund at any time for any reason. In addition, the Fund may waive certain requirements regarding the purchase, sale, exchange or transfer of shares described below.

Under certain circumstances, if no activity occurs in an account within a time period specified by state law, a shareholder’s shares in the Fund may be transferred to that state.

How to Buy Shares

	Your Choices	Important Information for You to Know
Initial Purchase	Determine the amount of your investment	There is no minimum initial investment for any Employer-Sponsored Retirement Plans or any other investors other than Institutional Investors. For Institutional Investors, there is a $5 million minimum initial investment for all accounts.

Table of Contents

	Your Choices	Important Information for You to Know
Initial Purchase (continued)	Have your Financial Intermediary submit your purchase order	The price of your shares is based on the next calculation of the Fund’s net asset value after your order is placed. Any purchase orders placed prior to the close of business on the New York Stock Exchange (the “NYSE”) (generally 4:00 p.m. Eastern time) will be priced at the net asset value determined that day. Certain Financial Intermediaries, however, may require submission of orders prior to that time. Purchase orders placed after that time will be priced at the net asset value determined on the next business day. A broker-dealer or financial institution maintaining the account in which you hold shares may charge a separate account, service or transaction fee on the purchase or sale of Fund shares that would be in addition to the fees and expenses shown in the Fund’s “Fees and Expenses” table. The Fund may reject any order to buy shares and may suspend the sale of shares at any time. Certain Financial Intermediaries may charge a processing fee to confirm a purchase.
	Or contact BlackRock (for accounts held directly with BlackRock)	For investors not purchasing shares through an Employer-Sponsored Retirement Plan, to purchase shares directly from BlackRock, call (800) 537-4942 and request a new account application.
Add to Your Investment	Purchase additional shares	There is no minimum investment amount for additional purchases.
	Have your Financial Intermediary submit your purchase order for additional shares	To purchase additional shares, you may contact your Financial Intermediary or Employer-Sponsored Retirement Plan.
	Or contact BlackRock (for accounts held directly with BlackRock)	For investors not purchasing shares through an Employer-Sponsored Retirement Plan: Purchase by Telephone: Call the Fund at (800) 537-4942 and speak with one of our representatives. The Fund has the right to reject any telephone request for any reason. Purchase by Internet: You may purchase your shares, and view activity in your account, by logging onto the BlackRock website at www.blackrock.com. Purchases made on the Internet using the Automated Clearing House (“ACH”) will have a trade date that is the day after the purchase is made. Certain institutional clients’ purchase orders placed by wire prior to the close of business on the NYSE will be priced at the net asset value determined that day. Contact your Financial Intermediary or BlackRock for further information. Limits on amounts that may be purchased via Internet may vary. For additional information call BlackRock at (800) 537-4942. Please read the On-Line Services Disclosure Statement and User Agreement, the Terms and Conditions page and the Consent to Electronic Delivery Agreement (if you consent to electronic delivery), before attempting to transact online. The Fund employs reasonable procedures to confirm that transactions entered over the Internet are genuine. By entering into the User Agreement with the Fund in order to open an account through the website, the shareholder waives any right to reclaim any losses from the Fund or any of its affiliates incurred through fraudulent activity.
	Acquire additional shares by reinvesting dividends and capital gains	All dividends and capital gains distributions are automatically reinvested in shares of the Fund at net asset value. To make any changes to your dividend and/or capital gains distributions options, please call BlackRock at (800) 537-4942 (for investors who are not purchasing shares through an Employer-Sponsored Retirement Plan) or contact your Financial Intermediary.

Table of Contents

	Your Choices	Important Information for You to Know
How to Pay for Shares	Making payment for purchases	If you are purchasing shares through an Employer-Sponsored Retirement Plan, payment for an order must be made in Federal funds or other immediately available funds by the time specified by your Financial Intermediary, but in no event later than 4:00 p.m. (Eastern time) on the first business day following the receipt of the order. If payment is not received by this time, the order will be canceled and you and your Financial Intermediary will be responsible for any loss to the Fund. If you are not purchasing shares through an Employer-Sponsored Retirement Plan, payment for shares must normally be made in Federal funds or other immediately available funds by the time specified by your Financial Intermediary but in no event later than 4:00 p.m. (Eastern time) on the first business day following the receipt of the order. Payment may also, at the discretion of the Fund, be made in the form of securities that are permissible investments for the respective fund. If payment is not received by this time, the order will be canceled and you and your Financial Intermediary will be responsible for any loss to the Fund.

How to Sell Shares

	Your Choices	Important Information for You to Know
Full or Partial Redemption of Shares	Have your Financial Intermediary submit your sales order	If you purchased shares through an Employer-Sponsored Retirement Plan, you can make redemption requests through your Financial Intermediary in accordance with the procedures applicable to your accounts. These procedures may vary according to the type of account and the Financial Intermediary involved, and customers should consult their Financial Intermediary in this regard. Financial Intermediaries are responsible for transmitting redemption orders and crediting their customers’ accounts with redemption proceeds on a timely basis. Information relating to such redemption services and charges to process a redemption of shares, if any, should be obtained by customers from their Financial Intermediaries. If you did not purchase your shares through an Employer-Sponsored Retirement Plan, you can make redemption requests through your Financial Intermediary. The price of Class K Shares is based on the next calculation of the Fund’s net asset value after your order is placed. For your redemption request to be priced at the net asset value on the day of your request, you must submit your request to your Financial Intermediary prior to that day’s close of business on the NYSE (generally, 4:00 p.m. Eastern time). Certain Financial Intermediaries, however, may require submission of orders prior to that time. Any redemption request placed after that time will be priced at the net asset value at the close of business on the next business day. Regardless of the method the Fund uses to make payment of your redemption proceeds (check or wire), your redemption proceeds typically will be sent one to two business days after your request is submitted, but in any event, within seven days. Certain Financial Intermediaries may charge a fee to process a redemption of shares. The Fund may reject an order to sell shares under certain circumstances.
	Selling shares held directly with BlackRock	Methods of Redeeming if You Did Not Purchase Your Shares Through an Employer-Sponsored Retirement Plan Redeem by Telephone: You may sell shares held at BlackRock by telephone request. Call (800) 537-4942 for details. The Fund, its administrator and the Distributor will employ reasonable procedures to confirm that instructions communicated by telephone are genuine. The Fund and its service providers will not be liable for any loss, liability, cost or expense for acting upon telephone instructions

Table of Contents

	Your Choices	Important Information for You to Know
Full or Partial Redemption of Shares (continued)	Selling shares held directly with BlackRock (continued)	that are reasonably believed to be genuine in accordance with such procedures. The Fund may refuse a telephone redemption request if it believes it is advisable to do so. During periods of substantial economic or market change, telephone redemptions may be difficult to complete. Please find alternative redemption methods below. Redeem by Internet: You may redeem in your account, by logging onto the BlackRock website at www.blackrock.com. Proceeds from Internet redemptions will be sent via wire to the bank account of record. Redeem in Writing: Redemption requests may be sent in proper form to BlackRock, P.O. Box 9819, Providence, Rhode Island 02940-8019 or for overnight delivery, 4400 Computer Drive, Westborough, Massachusetts 01581. Under certain circumstances, a medallion signature guarantee will be required. Payment of Redemption Proceeds Redemption proceeds may be paid by check or, if the Fund has verified banking information on file, by wire transfer. Payment by Check: BlackRock will normally mail redemption proceeds within three business days following receipt of a properly completed request, but in any event within seven days. Shares can be redeemed by telephone and the proceeds sent by check to the shareholder at the address on record. Shareholders will pay $15 for redemption proceeds sent by check via overnight mail. You are responsible for any additional charges imposed by your bank for this service. The Fund reserves the right to reinvest any dividend or distribution amounts (e.g., income dividends or capital gains) which you have elected to receive by check should your check be returned as undeliverable or remain uncashed for more than 6 months. No interest will accrue on amounts represented by uncashed checks. Your check will be reinvested in your account at the net asset value next calculated, on the day of the investment. When reinvested, those amounts are subject to the risk of loss like any fund investment. If you elect to receive distributions in cash and a check remains undeliverable or uncashed for more than 6 months, your cash election may also be changed automatically to reinvest and your future dividend and capital gains distributions will be reinvested in the Fund at the net asset value as of the date of payment of the distribution. Payment by Wire Transfer: Payment for redeemed shares for which a redemption order is received before 4:00 p.m. (Eastern time) on a business day is normally made in Federal funds wired to the redeeming shareholder on the next business day, provided that the Fund’s custodian is also open for business. Payment for redemption orders received after 4:00 p.m. (Eastern time) or on a day when the Fund’s custodian is closed is normally wired in Federal funds on the next business day following redemption on which the Fund’s custodian is open for business. The Fund reserves the right to wire redemption proceeds within seven days after receiving a redemption order if, in the judgment of the Fund, an earlier payment could adversely affect the Fund. Shares can be redeemed by Federal wire transfer to a single previously designated bank account. No charge for wiring redemption payments with respect to Class K Shares is imposed by the Fund. You are responsible for any additional charges imposed by your bank for wire transfers. The Fund is not responsible for the efficiency of the Federal wire system or the shareholder’s firm or bank. To change the name of the single, designated bank account to receive wire redemption proceeds, it is necessary to send a written request to the Fund at the address on the back cover of this prospectus. ***

Table of Contents

	Your Choices	Important Information for You to Know
Full or Partial Redemption of Shares (continued)	Selling shares held directly with BlackRock (continued)	If you make a redemption request before the Fund has collected payment for the purchase of shares, the Fund may delay mailing your proceeds. This delay will usually not exceed ten days.
Redemption Proceeds		Under normal circumstances, the Fund expects to meet redemption requests by using cash or cash equivalents in its portfolio or by selling portfolio assets to generate cash. During periods of stressed market conditions, when a significant portion of the Fund’s portfolio may be comprised of less-liquid investments, the Fund may be more likely to limit cash redemptions and may determine to pay redemption proceeds by (i) borrowing under a line of credit it has entered into with a group of lenders, (ii) borrowing from another BlackRock Fund pursuant to an interfund lending program, to the extent permitted by the Fund’s investment policies and restrictions as set forth in the SAI, and/or (iii) transferring portfolio securities in-kind to you. The SAI includes more information about the Fund’s line of credit and interfund lending program, to the extent applicable. If the Fund pays redemption proceeds by transferring portfolio securities in-kind to you, you may pay transaction costs to dispose of the securities, and you may receive less for them than the price at which they were valued for purposes of redemption.

How to Exchange Shares or Transfer Your Account

	Your Choices	Important Information for You to Know
Exchange Privilege	Selling shares of one BlackRock Fund to purchase shares of another BlackRock Fund (“exchanging”)	Class K Shares of the Fund are generally exchangeable for shares of the same class of another BlackRock Fund, to the extent such shares are offered by your Financial Intermediary. Investors who currently own Class K Shares of the Fund may make exchanges into Class K Shares of other BlackRock Funds except for investors holding shares through certain client accounts at Financial Intermediaries that are omnibus with the Fund and do not meet applicable minimums. There is no required minimum amount with respect to exchanges of Class K Shares. You may only exchange into Class K Shares of a BlackRock Fund that is open to new investors or in which you have a current account, if the BlackRock Fund is closed to new investors. To exercise the exchange privilege, you may contact your Financial Intermediary. Alternatively, if your account is held directly with BlackRock, you may: (i) call (800) 537-4942 and speak with one of our representatives, (ii) make the exchange via the Internet by accessing your account online at www.blackrock.com, or (iii) send a written request to the Fund at the address on the back cover of this prospectus. Please note, if you indicated on your new account application that you did not want the Telephone Exchange Privilege, you will not be able to place exchanges via the telephone until you update this option either in writing or by calling (800) 537-4942. The Fund has the right to reject any telephone request for any reason. Although there is currently no limit on the number of exchanges that you can make, the exchange privilege may be modified or terminated at any time in the future. The Fund may suspend or terminate your exchange privilege at any time for any reason, including if the Fund believes, in its sole discretion, that you are engaging in market timing activities. See “Short-Term Trading Policy” below. For U.S. federal income tax purposes a share exchange is a taxable event and a capital gain or loss may be realized. Please consult your tax adviser or other Financial Intermediary before making an exchange request.
Transfer Shares to Another Financial Intermediary	Transfer to a participating Financial Intermediary	You may transfer your Class K Shares of the Fund only to another Financial Intermediary that has entered into an agreement with the Distributor. Certain shareholder services may not be available for the transferred shares. All future trading of these assets must be coordinated by the receiving firm. Please contact your Financial Intermediary to accomplish the transfer of your Class K Shares.

Table of Contents

	Your Choices	Important Information for You to Know
Transfer Shares to Another Financial Intermediary (continued)	Transfer to a non-participating Financial Intermediary	You must either: • Transfer your Class K Shares to an account with the Fund; or • Sell your Class K Shares. Please contact your Financial Intermediary to accomplish the transfer of your Class K Shares.

Additional Purchase and Redemption Information Applicable to the Fund if You Are Not Purchasing Shares Through an Employer-Sponsored Retirement Plan

If you are not purchasing shares through an Employer-Sponsored Retirement Plan, the Fund may authorize one or more banks, savings and loan associations and other financial institutions (each a “Service Organization”) to accept purchase and redemption orders on its behalf. Such Service Organizations may be authorized to designate other intermediaries to accept purchase and redemption orders on the Fund’s behalf. If you purchase or redeem shares through a Service Organization or its designee, that entity may have its own deadlines for the receipt of the purchase or redemption order that may be earlier than those stated in the prospectus. The Fund will be deemed to have received a purchase or redemption order when a Service Organization or, if applicable, that Service Organization’s authorized designee, accepts the order. These orders will be priced at the Fund’s net asset value per share next calculated after they are so accepted.

Fund’s Rights

The Fund may:

■	Suspend the right of redemption if trading is halted or restricted on the NYSE or under other emergency conditions described in the Investment Company Act;
■	Postpone the date of payment upon redemption if trading is halted or restricted on the NYSE or under other emergency conditions described in the Investment Company Act or if a redemption request is made before the Fund has collected payment for the purchase of shares;
■	Redeem shares for property other than cash as may be permitted under the Investment Company Act; and
■	Redeem shares involuntarily in certain cases, such as when the value of a shareholder account falls below a specified level.

Note on Low Balance Accounts. Because of the high cost of maintaining smaller shareholder accounts, BlackRock has set a minimum balance of $500 in each Fund position you hold within your account (“Fund Minimum”), and may redeem the shares in your account if the net asset value of those shares in your account falls below $500 for any reason, including market fluctuation.

You will be notified that the value of your account is less than the Fund Minimum before the Fund makes any involuntary redemption. This notification will provide you with a 90 calendar day period to make an additional investment in order to bring the value of your account to at least $500 before the Fund makes an involuntary redemption. This involuntary redemption will not charge any deferred sales charge, and may not apply to accounts of certain employer-sponsored retirement plans (not including IRAs), qualified state tuition plan (529 Plan) accounts, and select fee-based programs at your Financial Intermediary.

Short-Term Trading Policy

The Board of Directors (the “Board”) has determined that the interests of long-term shareholders and the Fund’s ability to manage its investments may be adversely affected when shares are repeatedly bought, sold or exchanged in response to short-term market fluctuations — also known as “market timing.” The Fund is not designed for market timing organizations or other entities using programmed or frequent purchases and sales or exchanges. The exchange privilege is not intended as a vehicle for short-term trading. Excessive purchase and sale or exchange activity may interfere with portfolio management, increase expenses and taxes and may have an adverse effect on the performance of the Fund and its returns to shareholders. For example, large flows of cash into and out of the Fund may require the management team to allocate a significant amount of assets to cash or other short-term investments or sell securities, rather than maintaining such assets in securities selected to achieve the Fund’s investment objective. Frequent trading may cause the Fund to sell securities at less favorable prices, and transaction costs, such as brokerage commissions, can reduce the Fund’s performance.

Table of Contents

A fund’s investment in non-U.S. securities is subject to the risk that an investor may seek to take advantage of a delay between the change in value of the fund’s portfolio securities and the determination of the fund’s net asset value as a result of different closing times of U.S. and non-U.S. markets by buying or selling fund shares at a price that does not reflect their true value. A similar risk exists for funds that invest in securities of small capitalization companies, securities of issuers located in emerging markets or high yield securities (junk bonds) that are thinly traded and therefore may have actual values that differ from their market prices. This short-term arbitrage activity can reduce the return received by long-term shareholders. The Fund will seek to eliminate these opportunities by using fair value pricing, as described in “Management of the Fund — Valuation of Fund Investments” below.

The Fund discourages market timing and seeks to prevent frequent purchases and sales or exchanges of Fund shares that it determines may be detrimental to the Fund or long-term shareholders. The Board has approved the policies discussed below to seek to deter market timing activity. The Board has not adopted any specific numerical restrictions on purchases, sales and exchanges of Fund shares because certain legitimate strategies will not result in harm to the Fund or its shareholders.

If as a result of its own investigation, information provided by a Financial Intermediary or other third party, or otherwise, the Fund believes, in its sole discretion, that your short-term trading is excessive or that you are engaging in market timing activity, it reserves the right to reject any specific purchase or exchange order. If the Fund rejects your purchase or exchange order, you will not be able to execute that transaction, and the Fund will not be responsible for any losses you therefore may suffer. For transactions placed directly with the Fund, the Fund may consider the trading history of accounts under common ownership or control for the purpose of enforcing these policies. Transactions placed through the same Financial Intermediary on an omnibus basis may be deemed part of a group for the purpose of this policy and may be rejected in whole or in part by the Fund. Certain accounts, such as omnibus accounts and accounts at Financial Intermediaries, however, include multiple investors and such accounts typically provide the Fund with net purchase or redemption and exchange requests on any given day where purchases, redemptions and exchanges of shares are netted against one another and the identity of individual purchasers, redeemers and exchangers whose orders are aggregated may not be known by the Fund. While the Fund monitors for market timing activity, the Fund may be unable to identify such activities because the netting effect in omnibus accounts often makes it more difficult to locate and eliminate market timers from the Fund. The Distributor has entered into agreements with respect to Financial Intermediaries that maintain omnibus accounts with the Transfer Agent pursuant to which such Financial Intermediaries undertake to cooperate with the Distributor in monitoring purchase, exchange and redemption orders by their customers in order to detect and prevent short-term or excessive trading in the Fund’s shares through such accounts. Identification of market timers may also be limited by operational systems and technical limitations. In the event that a Financial Intermediary is determined by the Fund to be engaged in market timing or other improper trading activity, the Fund’s Distributor may terminate such Financial Intermediary’s agreement with the Distributor, suspend such Financial Intermediary’s trading privileges or take other appropriate actions.

There is no assurance that the methods described above will prevent market timing or other trading that may be deemed abusive.

The Fund may from time to time use other methods that it believes are appropriate to deter market timing or other trading activity that may be detrimental to the Fund or long-term shareholders.

Table of Contents

Management of the Fund

BlackRock

BlackRock, the Fund’s investment adviser, manages the Fund’s investments and its business operations subject to the oversight of the Board of the Corporation. While BlackRock is ultimately responsible for the management of the Fund, it is able to draw upon the trading, research and expertise of its asset management affiliates for portfolio decisions and management with respect to certain portfolio securities. BlackRock is an indirect, wholly-owned subsidiary of BlackRock, Inc.

BlackRock, a registered investment adviser, was organized in 1994 to perform advisory services for investment companies. BlackRock International Limited (“BIL”) and BlackRock (Singapore) Limited (“BRS”), the Fund’s sub-advisers (the “Sub-Advisers”), are registered investment advisers organized in 1995 and 2000, respectively. BlackRock and its affiliates had approximately $8.676 trillion in investment company and other portfolio assets under management as of December 31, 2020.

The Corporation, on behalf of the Fund, has entered into a management agreement with BlackRock. Under the management agreement, BlackRock receives compensation for investment advisory and certain administrative services it provides to the Fund. The Fund invests all of its assets in interests of the Master Portfolio. For the Fund, therefore, all portfolio management occurs at the Master Portfolio level. Pursuant to the terms of a management agreement between the Master LLC, on behalf of the Master Portfolio, and BlackRock, subject to the oversight of the Board of Directors of the Master LLC, BlackRock provides investment advisory and certain administrative services to the Master Portfolio and receives as compensation for its services a fee with respect to the Master Portfolio. The management agreements between BlackRock and the Corporation and the Master LLC are collectively referred to as the “Management Agreements.”

Under the Management Agreements, BlackRock receives for its services to each of the Fund and the Master Portfolio a fee as a percentage of average daily net assets. With respect to the Fund and the Master Portfolio, the maximum actual management fees payable to BlackRock (as a percentage of average daily net assets) are calculated as follows:

	Rates of Management Fees
Average Daily Net Assets	Total Return Fund¹	Master Portfolio
First $250 million	0.32%	0.16%
$250 million – $500 million	0.31%	0.12%
$500 million – $750 million	0.30%	0.08%
Over $750 million	0.29%	0.05%

Under the terms of the management agreement between the Corporation, on behalf of the Fund, and BlackRock, this contractual management fee applies to the Fund for as long as the Fund invests in the Master Portfolio or another master fund advised by BlackRock or an affiliate thereof in a master/feeder structure. If the Fund ceases to operate as a feeder fund in a master/feeder structure, the maximum actual management fees payable to BlackRock (as a percentage of average daily net assets) by the Fund are as follows: 0.48% (first $250 million), 0.43% ($250 million – $500 million), 0.38% ($500 million – $750 million) and 0.34% (over $750 million).

With the exception of the Fund’s investment in the Master Portfolio, BlackRock has contractually agreed to waive the management fee of the Fund and the Master Portfolio with respect to any portion of the Fund’s and the Master Portfolio’s assets estimated to be attributable to investments in other equity and fixed-income mutual funds and ETFs managed by BlackRock or its affiliates that have a contractual management fee, through January 31, 2022. In addition, BlackRock has contractually agreed to waive its management fees by the amount of investment advisory fees the Fund or the Master Portfolio pays to BlackRock indirectly through its investment in money market funds managed by BlackRock or its affiliates (the “affiliated money market fund waiver”), through January 31, 2022. The contractual agreements may be terminated upon 90 days’ notice by a majority of the non-interested directors of the Corporation or the Master Portfolio or by a vote of a majority of the outstanding voting securities of the Fund or the Master Portfolio.

Table of Contents

For the fiscal year ended September 30, 2020, BlackRock received management fees, net of any applicable waivers, as a percentage of the average daily net assets of the Fund or Master Portfolio, as applicable, as follows:

Fund	Management Fees (Net of Applicable Waivers)
Total Return Fund	0.29%
Master Portfolio	0.05%

BlackRock has entered into sub-advisory agreements with the Sub-Advisers, affiliates of BlackRock. Under the sub-advisory agreements, BlackRock pays the Sub-Advisers for services they provide for that portion of the Fund for which each Sub-Adviser acts as sub-adviser a fee equal to a percentage of the management fee paid to BlackRock under the Management Agreements.

BlackRock has agreed to cap net expenses (excluding (i) interest, taxes, dividends tied to short sales, brokerage commissions, and other expenditures which are capitalized in accordance with generally accepted accounting principles; (ii) expenses incurred directly or indirectly by the Fund as a result of investments in other investment companies and pooled investment vehicles; (iii) other expenses attributable to, and incurred as a result of, the Fund’s investments; and (iv) extraordinary expenses (including litigation expenses) not incurred in the ordinary course of the Fund’s business, if any) of each share class of the Fund at the levels shown below and in the Fund’s fees and expenses table in the Fund Overview section of this prospectus. Items (i), (ii), (iii) and (iv) in the preceding sentence are referred to in this prospectus as “Dividend Expense, Interest Expense, Acquired Fund Fees and Expenses and certain other Fund expenses.” To achieve these expense caps, BlackRock has agreed to waive and/or reimburse fees or expenses if these operating expenses exceed a certain limit.

With respect to the Fund, BlackRock has contractually agreed to waive and/or reimburse fees or expenses in order to limit Total Annual Fund Operating Expenses to the amounts noted in the table below.

	Contractual Cap on Total Annual Fund Operating Expenses^* (excluding Dividend Expense, Interest Expense, Acquired Fund Fees and Expenses and certain other Fund expenses)¹
Class K Shares	0.39%

*	As a percentage of average daily net assets.
¹	The contractual cap is in effect through January 31, 2022. The contractual agreement may be terminated upon 90 days’ notice by a majority of the non-interested directors of the Corporation or by a vote of a majority of the outstanding voting securities of the Fund.

The amount of the contractual waivers and/or reimbursements of fees and expenses made pursuant to the contractual cap on net expenses will be reduced by the amount of the affiliated money market fund waiver.

A discussion of the basis for the Board’s approval of the Management Agreements with BlackRock and the sub-advisory agreements between BlackRock and each of BIL and BRS with respect to the Fund is included in the Fund’s annual shareholder report for the fiscal year ended September 30, 2020.

From time to time, a manager, analyst, or other employee of BlackRock or its affiliates may express views regarding a particular asset class, company, security, industry, or market sector. The views expressed by any such person are the views of only that individual as of the time expressed and do not necessarily represent the views of BlackRock or any other person within the BlackRock organization. Any such views are subject to change at any time based upon market or other conditions and BlackRock disclaims any responsibility to update such views. These views may not be relied on as investment advice and, because investment decisions for the Fund are based on numerous factors, may not be relied on as an indication of trading intent on behalf of the Fund.

Legal Proceedings. On May 27, 2014, certain investors in the BlackRock Global Allocation Fund, Inc. (“Global Allocation”) and the BlackRock Equity Dividend Fund (“Equity Dividend”) filed a consolidated complaint in the United States District Court for the District of New Jersey against BlackRock Advisors, LLC, BlackRock Investment Management, LLC and BlackRock International Limited (collectively, the “Defendants”) under the caption In re BlackRock Mutual Funds Advisory Fee Litigation. In the lawsuit, which purports to be brought derivatively on behalf of Global Allocation and Equity Dividend, the plaintiffs allege that the Defendants violated Section 36(b) of the Investment Company Act by receiving allegedly excessive investment advisory fees from Global Allocation and Equity Dividend. On June 13, 2018, the court granted in part and denied in part the Defendants’ motion for summary judgment. On July 25, 2018, the plaintiffs served a pleading that supplemented the time period of their alleged damages to run through the date of trial. The lawsuit seeks, among other things, to recover on behalf of Global Allocation and Equity

Table of Contents

Dividend all allegedly excessive advisory fees received by the Defendants beginning twelve months preceding the start of the lawsuit with respect to each of Global Allocation and Equity Dividend and ending on the date of judgment, along with purported lost investment returns on those amounts, plus interest. The trial on the remaining issues was completed on August 29, 2018. On February 8, 2019, the court issued an order dismissing the claims in their entirety. On March 8, 2019, the plaintiffs provided notice that they were appealing both the February 8, 2019 post-trial order and the June 13, 2018 order partially granting Defendants’ motion for summary judgment. On May 28, 2020, the appellate court affirmed the trial court’s orders. On June 26, 2020, the plaintiffs petitioned the appeals court for a rehearing, which was denied on July 9, 2020. Plaintiffs’ deadline to seek further appeal has passed; consequently, this matter is now closed.

Portfolio Manager Information

Information regarding the portfolio managers of the Fund is set forth below. Further information regarding the portfolio managers, including other accounts managed, compensation, ownership of Fund shares, and possible conflicts of interest, is available in the Fund’s SAI.

Portfolio Manager	Primary Role	Since	Title and Recent Biography
Rick Rieder	Responsible for the day-to-day management of the Fund’s portfolio including setting the Fund’s overall investment strategy and overseeing the management of the Fund.	2010	Chief Investment Officer of Global Fixed Income, Head of Global Allocation Investment Team in the Multi-Asset Strategies Group, member of Global Operating Committee and Chairman of the BlackRock, Inc. firmwide Investment Council; Managing Director of BlackRock, Inc. since 2009; President and Chief Executive Officer of R3 Capital Partners from 2008 to 2009; Managing Director of Lehman Brothers from 1994 to 2008.
Bob Miller	Responsible for the day-to-day management of the Fund’s portfolio including setting the Fund’s overall investment strategy and overseeing the management of the Fund.	2011	Managing Director of BlackRock, Inc. since 2011; Co-Founder and Partner of Round Table Investment Management Company from 2007 to 2009; Managing Director of Bank of America from 1999 to 2007.
David Rogal	Responsible for the day-to-day management of the Fund’s portfolio including setting the Fund’s overall investment strategy and overseeing the management of the Fund.	2017	Managing Director of BlackRock, Inc. since 2019; Director of BlackRock, Inc. from 2014 to 2018; Vice President of BlackRock, Inc. from 2011 to 2013.

Conflicts of Interest

The investment activities of BlackRock and its affiliates (including BlackRock, Inc. and its subsidiaries (collectively, the “Affiliates”)), and their respective directors, officers or employees, in the management of, or their interest in, their own accounts and other accounts they manage, may present conflicts of interest that could disadvantage the Fund and its shareholders.

BlackRock and its Affiliates provide investment management services to other funds and discretionary managed accounts that may follow investment programs similar to that of the Fund. BlackRock and its Affiliates are involved worldwide with a broad spectrum of financial services and asset management activities and may engage in the ordinary course of business in activities in which their interests or the interests of their clients may conflict with those of the Fund. BlackRock or one or more Affiliates act or may act as an investor, research provider, investment manager, commodity pool operator, commodity trading advisor, financier, underwriter, adviser, trader, lender, index provider, agent and/or principal, and have other direct and indirect interests in securities, currencies, commodities, derivatives and other instruments in which the Fund may directly or indirectly invest. The Fund may invest in securities of, or engage in other transactions with, companies with which an Affiliate has significant debt or equity investments or other interests. The Fund may also invest in issuances (such as structured notes) by entities for which an Affiliate provides and is compensated for cash management services relating to the proceeds from the sale of such issuances. The Fund also may invest in securities of, or engage in other transactions with, companies for which an Affiliate provides or

Table of Contents

may in the future provide research coverage. An Affiliate may have business relationships with, and purchase, or distribute or sell services or products from or to, distributors, consultants or others who recommend the Fund or who engage in transactions with or for the Fund, and may receive compensation for such services. BlackRock or one or more Affiliates may engage in proprietary trading and advise accounts and funds that have investment objectives similar to those of the Fund and/or that engage in and compete for transactions in the same types of securities, currencies and other instruments as the Fund. This may include transactions in securities issued by other open-end and closed-end investment companies (which may include investment companies that are affiliated with the Fund and BlackRock, to the extent permitted under the Investment Company Act). The trading activities of BlackRock and these Affiliates are carried out without reference to positions held directly or indirectly by the Fund and may result in BlackRock or an Affiliate having positions in certain securities that are senior or junior to, or have interests different from or adverse to, the securities that are owned by the Fund.

Neither BlackRock nor any Affiliate is under any obligation to share any investment opportunity, idea or strategy with the Fund. As a result, an Affiliate may compete with the Fund for appropriate investment opportunities. The results of the Fund’s investment activities, therefore, may differ from those of an Affiliate and of other accounts managed by BlackRock or an Affiliate, and it is possible that the Fund could sustain losses during periods in which one or more Affiliates and other accounts achieve profits on their trading for proprietary or other accounts. The opposite result is also possible.

In addition, the Fund may, from time to time, enter into transactions in which BlackRock or an Affiliate or their directors, officers or employees or other clients have an adverse interest. Furthermore, transactions undertaken by clients advised or managed by BlackRock or its Affiliates may adversely impact the Fund. Transactions by one or more clients or BlackRock or its Affiliates or their directors, officers or employees, may have the effect of diluting or otherwise disadvantaging the values, prices or investment strategies of the Fund. The Fund’s activities may be limited because of regulatory restrictions applicable to BlackRock or one or more Affiliates and/or their internal policies designed to comply with such restrictions.

Under a securities lending program approved by the Master LLC’s Board, the Master LLC has retained BlackRock Investment Management, LLC, an Affiliate of BlackRock, to serve as the securities lending agent for the Master LLC to the extent that the Master LLC participates in the securities lending program. For these services, the securities lending agent will receive a fee from the Master LLC, including a fee based on the returns earned on the Master LLC’s investment of the cash received as collateral for the loaned securities. In addition, one or more Affiliates may be among the entities to which the Master LLC may lend its portfolio securities under the securities lending program.

The activities of BlackRock and its Affiliates and their respective directors, officers or employees, may give rise to other conflicts of interest that could disadvantage the Fund and its shareholders. BlackRock has adopted policies and procedures designed to address these potential conflicts of interest. See the SAI for further information.

Master/Feeder Structure

The Fund is a “feeder” fund that invests all of its assets in the Master Portfolio. Investors in the Fund will acquire an indirect interest in the Master Portfolio.

The Master Portfolio may accept investments from other feeder funds, and all the feeders of the Master Portfolio bear the portfolio’s expenses in proportion to their assets. This structure may enable the Fund to reduce costs through economies of scale. A larger investment portfolio may also reduce certain transaction costs to the extent that contributions to and redemptions from the Master Portfolio from different feeders may offset each other and produce a lower net cash flow.

However, each feeder can set its own transaction minimums, fund-specific expenses, and other conditions. This means that one feeder could offer access to the Master Portfolio on more attractive terms, or could experience better performance, than another feeder. In addition, large purchases or redemptions by one feeder fund could negatively affect the performance of other feeder funds that invest in the Master Portfolio. Information about other feeders, if any, is available by calling (800) 441-7762.

Whenever the Master Portfolio holds a vote of its feeder funds, the Fund will pass the vote through to its own shareholders. Smaller feeder funds may be harmed by the actions of larger feeder funds. For example, a larger feeder fund could have more voting power than the Fund over the operations of the Master Portfolio.

The Fund may withdraw from the Master Portfolio at any time and may invest all of its assets in another pooled investment vehicle or have an investment adviser manage the Fund’s assets directly.

Table of Contents

Valuation of Fund Investments

When you buy shares, you pay the net asset value. This is the offering price. Shares are also redeemed at their net asset value. The Fund calculates the net asset value of each class of its shares each day the NYSE is open, generally as of the close of regular trading hours on the NYSE, based on prices at the time of closing. The NYSE generally closes at 4:00 p.m. (Eastern time). The net asset value used in determining your share price is the next one calculated after your purchase or redemption order is received.

Equity securities and other instruments for which market quotations are readily available are valued at market value, which is generally determined using the last reported closing price or, if a reported closing price is not available, the last traded price on the exchange or market on which the security or instrument is primarily traded at the time of valuation. The Fund values fixed-income portfolio securities and non-exchange traded derivatives using last available bid prices or current market quotations provided by dealers or prices (including evaluated prices) supplied by the Fund’s approved independent third-party pricing services, each in accordance with valuation procedures approved by the Board. Pricing services may use matrix pricing or valuation models that utilize certain inputs and assumptions to derive values. Pricing services generally value fixed-income securities assuming orderly transactions of institutional round lot size, but the Fund may hold or transact in such securities in smaller, odd lot sizes. Odd lots may trade at lower prices than institutional round lots. Short-term debt securities with remaining maturities of 60 days or less may be valued on the basis of amortized cost.

Foreign currency exchange rates are generally determined as of the close of business on the NYSE. Foreign securities owned by the Fund may trade on weekends or other days when the Fund does not price its shares. As a result, the Fund’s net asset value may change on days when you will not be able to purchase or redeem the Fund’s shares.

Generally, trading in foreign securities, U.S. Government securities, money market instruments and certain fixed-income securities is substantially completed each day at various times prior to the close of business on the NYSE. The values of such securities used in computing the net asset value of the Fund’s shares are determined as of such times.

When market quotations are not readily available or are not believed by BlackRock to be reliable, the Fund’s investments are valued at fair value. Fair value determinations are made by BlackRock in accordance with procedures approved by the Board. BlackRock may conclude that a market quotation is not readily available or is unreliable if a security or other asset or liability does not have a price source due to its lack of liquidity, if BlackRock believes a market quotation from a broker-dealer or other source is unreliable, where the security or other asset or other liability is thinly traded (e.g., municipal securities, certain small cap and emerging growth companies, and certain non-U.S. securities) or where there is a significant event subsequent to the most recent market quotation. For this purpose, a “significant event” is deemed to occur if BlackRock determines, in its business judgment prior to or at the time of pricing the Fund’s assets or liabilities, that it is likely that the event will cause a material change to the last closing market price of one or more assets or liabilities held by the Fund. For instance, significant events may occur between the foreign market close and the close of business on the NYSE that may not be reflected in the computation of the Fund’s net assets. If such event occurs, those instruments may be fair valued. Similarly, foreign securities whose values are affected by volatility that occurs in U.S. markets on a trading day after the close of foreign securities markets may be fair valued.

For certain foreign securities, a third-party vendor supplies evaluated, systematic fair value pricing based upon the movement of a proprietary multi-factor model after the relevant foreign markets have closed. This systematic fair value pricing methodology is designed to correlate the prices of foreign securities following the close of the local markets to the price that might have prevailed as of the Fund’s pricing time.

Fair value represents a good faith approximation of the value of a security. The fair value of one or more securities may not, in retrospect, be the price at which those assets could have been sold during the period in which the particular fair values were used in determining the Fund’s net asset value.

The Fund may accept orders from certain authorized Financial Intermediaries or their designees. The Fund will be deemed to receive an order when accepted by the Financial Intermediary or designee, and the order will receive the net asset value next computed by the Fund after such acceptance. If the payment for a purchase order is not made by a designated later time, the order will be canceled and the Financial Intermediary could be held liable for any losses.

Table of Contents

Dividends, Distributions and Taxes

BUYING A DIVIDEND

Unless your investment is in a tax-deferred account, you may want to avoid buying shares shortly before the Fund pays a dividend. The reason? If you buy shares when the Fund has declared but not yet distributed ordinary income or capital gains, you will pay the full price for the shares and then receive a portion of the price back in the form of a taxable dividend. Before investing you may want to consult your tax adviser.

The Fund will distribute net investment income, if any, monthly and net realized capital gain, if any, at least annually. The Fund may also pay a special distribution at the end of the calendar year to comply with federal tax requirements. Dividends may be reinvested automatically in shares of the Fund at net asset value or may be taken in cash. If you would like to receive dividends in cash, contact your Financial Intermediary or the Fund.

Your tax consequences from an investment in the Fund will depend on whether you have invested through a qualified tax-exempt plan described in section 401(a) of the Internal Revenue Code (a “Qualified Plan”).

Investments Through a Qualified Plan

Special tax rules apply to investments made through Qualified Plans. If you are invested through a Qualified Plan (and Fund shares are not “debt-financed property” to the plan), then you will not be subject to U.S. federal income tax on the dividends paid by the Fund or the gain realized from a redemption or exchange of Fund shares until you withdraw or receive distributions from the plan. Distributions you receive from the Qualified Plan may be subject to U.S. federal withholding tax depending on the kind of payment you receive.

Investments Not Made Through Qualified Plans

If you are not invested through a Qualified Plan, you will generally pay tax on dividends from the Fund whether you receive them in cash or additional shares. If you redeem Fund shares or exchange them for shares of another fund, you generally will be treated as having sold your shares and any gain on the transaction may be subject to tax. Fund distributions derived from qualified dividend income, which consists of dividends received from U.S. corporations and qualifying foreign corporations, and long-term capital gains, are eligible for taxation at a maximum rate of 15% or 20% for individuals, depending on whether their income exceeds certain threshold amounts, which are adjusted annually for inflation.

A 3.8% Medicare tax is imposed on the net investment income (which includes, but is not limited to, interest, dividends and net gain from investments) of U.S. individuals with income exceeding $200,000, or $250,000 if married filing jointly, and of trusts and estates.

Your dividends and redemption proceeds will be subject to backup withholding tax if you have not provided a taxpayer identification number or social security number or the number you have provided is incorrect.

Special Considerations for Non-U.S. Persons

If you are not invested through a Qualified Plan and you are neither a tax resident nor a citizen of the United States or if you are a foreign entity (other than a pass-through entity to the extent owned by U.S. persons), the Fund’s ordinary income dividends will generally be subject to a 30% U.S. withholding tax, unless a lower treaty rate applies. However, certain distributions paid to a foreign shareholder and reported by the Fund as capital gain dividends, interest-related dividends or short-term capital gain dividends may be eligible for an exemption from U.S. withholding tax.

Separately, a 30% withholding tax is currently imposed on U.S.-source dividends, interest and other income items paid to (i) certain foreign financial institutions and investment funds, and (ii) certain other foreign entities. To avoid withholding, foreign financial institutions and investment funds will generally either need to (a) collect and report to the IRS detailed information identifying their U.S. accounts and U.S. account holders, comply with due diligence procedures for identifying U.S. accounts and withhold tax on certain payments made to noncomplying foreign entities and account holders or (b) if an intergovernmental agreement is entered into and implementing legislation is adopted, comply with the agreement and legislation. Other foreign entities will generally either need to provide detailed information identifying each substantial U.S. owner or certify there are no such owners.

This section summarizes some of the consequences under current federal tax law of an investment in the Fund. It is not a substitute for individualized tax advice. Consult your tax adviser about the potential tax consequences of an investment in the Fund under all applicable tax laws.

Table of Contents

Financial Highlights

The Financial Highlights table is intended to help you understand the Fund’s financial performance for the periods shown. Certain information reflects the financial results for a single Fund share. The total returns in the table represent the rate that an investor would have earned or lost on an investment in the Fund (assuming reinvestment of all dividends and/or distributions). The information has been audited by Deloitte & Touche LLP, whose report, along with the Fund’s financial statements, is included in the Fund’s Annual Report, which is available upon request.

	Class K
	Year Ended September 30,
(For a share outstanding throughout each period)	2020	2019	2018	2017	2016
Net asset value, beginning of year	$ 11.95	$ 11.21	$ 11.77	$ 11.95	$ 11.71
Net investment income^(a)	0.29	0.39	0.39	0.35	0.32
Net realized and unrealized gain (loss)	0.60	0.74	(0.56)	(0.17)	0.30
Net increase (decrease) from investment operations	0.89	1.13	(0.17)	0.18	0.62
Distributions from net investment income^(b)	(0.31)	(0.39)	(0.39)	(0.36)	(0.38)
Net asset value, end of year	$ 12.53	$ 11.95	$ 11.21	$ 11.77	$ 11.95
Total Return^(c)
Based on net asset value	7.59% ^(d)	10.30%	(1.49)% ^(d)	1.59%	5.44%
Ratios to Average Net Assets^(e)
Total expenses^(f)	0.37% ^(g)	0.37% ^(g)	0.64% ^(h)	0.64% ^(h)	0.52% ^(h)
Total expenses after fees waived and/or reimbursed^(f)	0.37% ^(g)	0.37% ^(g)	0.64% ^(h)	0.63% ^(h)	0.52% ^(h)
Total expenses after fees waived and/or reimbursed and excluding interest expense^(f)	0.37% ^(g)	0.37% ^(g)	0.38% ^(h)	0.39% ^(h)	0.39% ^(h)
Net investment income^(f)	2.41% ^(g)	3.40% ^(g)	3.36% ^(h)	3.00% ^(h)	2.73% ^(h)
Supplemental Data
Net assets, end of year (000)	$7,491,107	$6,015,062	$4,726,240	$3,751,146	$2,770,095
Portfolio turnover rate of the Master Portfolio⁽ⁱ⁾	556%	574%	734%	806%	841%

^(a)	Based on average shares outstanding.
^(b)	Distributions for annual periods determined in accordance with U.S. federal income tax regulations.
^(c)	Where applicable, assumes the reinvestment of distributions.
^(d)	Includes a payment received from an affiliate, which had no impact on the Fund’s total return.
^(e)	Includes the Fund’s share of the Master Portfolio’s allocated expenses and/or net investment income.
^(f)	Excludes expenses incurred indirectly as a result of investments in underlying funds as follows:

	Year Ended September 30,
	2020	2019	2018	2017	2016
Investments in underlying funds	0.01%	0.01%	0.01%	0.01%	0.01%

^(g)	Includes the Fund’s share of the Master Portfolio’s allocated fees waived of 0.01%.
^(h)	Includes the Fund’s share of the Master Portfolio’s allocated fees waived of less than 0.01%.
⁽ⁱ⁾	Includes MDRs. Additional information regarding portfolio turnover rate is as follows:

	Year Ended September 30,
	2020	2019	2018	2017	2016
Portfolio turnover rate (excluding MDRs)	274%	241%	350%	540%	598%

Table of Contents

General Information

Shareholder Documents

Electronic Access to Annual Reports, Semi-Annual Reports and Prospectuses

Electronic copies of most financial reports and prospectuses are available on BlackRock’s website. Shareholders can sign up for e-mail notifications of annual and semi-annual reports and prospectuses by enrolling in the Fund’s electronic delivery program. To enroll:

Shareholders Who Hold Accounts with Investment Advisers, Banks or Brokerages: Please contact your Financial Intermediary. Please note that not all investment advisers, banks or brokerages may offer this service.

Shareholders Who Hold Accounts Directly With BlackRock:

■	Access the BlackRock website at http://www.blackrock.com/edelivery; and
■	Log into your account.

Delivery of Shareholder Documents

The Fund delivers only one copy of shareholder documents, including prospectuses, shareholder reports and proxy statements, to shareholders with multiple accounts at the same address. This practice is known as “householding” and is intended to eliminate duplicate mailings and reduce expenses. Mailings of your shareholder documents may be householded indefinitely unless you instruct us otherwise. If you do not want the mailing of these documents to be combined with those for other members of your household, please contact the Fund at (800) 537-4942.

Certain Fund Policies

Anti-Money Laundering Requirements

The Fund is subject to the USA PATRIOT Act (the “Patriot Act”). The Patriot Act is intended to prevent the use of the U.S. financial system in furtherance of money laundering, terrorism or other illicit activities. Pursuant to requirements under the Patriot Act, the Fund is required to obtain sufficient information from shareholders to enable it to form a reasonable belief that it knows the true identity of its shareholders. This information will be used to verify the identity of investors or, in some cases, the status of Financial Intermediaries. Such information may be verified using third-party sources. This information will be used only for compliance with the Patriot Act or other applicable laws, regulations and rules in connection with money laundering, terrorism or economic sanctions.

The Fund reserves the right to reject purchase orders from persons who have not submitted information sufficient to allow the Fund to verify their identity. The Fund also reserves the right to redeem any amounts in the Fund from persons whose identity it is unable to verify on a timely basis. It is the Fund’s policy to cooperate fully with appropriate regulators in any investigations conducted with respect to potential money laundering, terrorism or other illicit activities.

BlackRock Privacy Principles

BlackRock is committed to maintaining the privacy of its current and former fund investors and individual clients (collectively, “Clients”) and to safeguarding their non-public personal information. The following information is provided to help you understand what personal information BlackRock collects, how we protect that information and why in certain cases we share such information with select parties.

If you are located in a jurisdiction where specific laws, rules or regulations require BlackRock to provide you with additional or different privacy-related rights beyond what is set forth below, then BlackRock will comply with those specific laws, rules or regulations.

BlackRock obtains or verifies personal non-public information from and about you from different sources, including the following: (i) information we receive from you or, if applicable, your Financial Intermediary, on applications, forms or other documents; (ii) information about your transactions with us, our affiliates, or others; (iii) information we receive from a consumer reporting agency; and (iv) from visits to our website.

Table of Contents

BlackRock does not sell or disclose to non-affiliated third parties any non-public personal information about its Clients, except as permitted by law, or as is necessary to respond to regulatory requests or to service Client accounts. These non-affiliated third parties are required to protect the confidentiality and security of this information and to use it only for its intended purpose.

We may share information with our affiliates to service your account or to provide you with information about other BlackRock products or services that may be of interest to you. In addition, BlackRock restricts access to non-public personal information about its Clients to those BlackRock employees with a legitimate business need for the information. BlackRock maintains physical, electronic and procedural safeguards that are designed to protect the non-public personal information of its Clients, including procedures relating to the proper storage and disposal of such information.

Statement of Additional Information

If you would like further information about the Fund, including how it invests, please see the SAI.

For a discussion of the Fund’s policies and procedures regarding the selective disclosure of its portfolio holdings, please see the SAI. The Fund makes its top ten holdings available on a monthly basis at www.blackrock.com generally within 5 business days after the end of the month to which the information applies.

Table of Contents

Glossary

This glossary contains an explanation of some of the common terms used in this prospectus. For additional information about the Fund, please see the SAI.

Acquired Fund Fees and Expenses — fees and expenses charged by other investment companies in which the Fund invests a portion of its assets.

Annual Fund Operating Expenses — expenses that cover the costs of operating the Fund.

Bloomberg Barclays U.S. Aggregate Bond Index — a broad-based flagship benchmark that measures the investment grade, U.S. dollar-denominated, fixed-rate taxable bond market. The index includes U.S. Treasuries, government-related and corporate securities, mortgage-backed securities (agency fixed-rate pass-throughs), asset-backed securities and commercial mortgage-backed securities (agency and non-agency).

Distribution Fees — fees used to support the Fund’s marketing and distribution efforts, such as compensating Financial Intermediaries, advertising and promotion.

Management Fee — a fee paid to BlackRock for managing the Fund.

Other Expenses — include accounting, transfer agency, custody, professional fees and registration fees.

Service Fees — fees used to compensate Financial Intermediaries for certain shareholder servicing activities.

Shareholder Fees — fees paid directly by a shareholder, including sales charges that you may pay when you buy or sell shares of the Fund.

Table of Contents

Additional Information

For more information:
This prospectus contains important information you should know before investing, including information about risks. Please read it before you invest and keep it for future reference. More information about the Fund is available at no charge upon request. This information includes:

Annual/Semi-Annual Reports
These reports contain additional information about each of the Fund’s investments. The annual report describes the Fund’s performance, lists portfolio holdings, and discusses recent market conditions, economic trends and Fund investment strategies that significantly affected the Fund’s performance for the last fiscal year.

Statement of Additional Information
A Statement of Additional Information (“SAI”), dated January 28, 2021, has been filed with the Securities and Exchange Commission (the “SEC”). The SAI, which includes additional information about the Fund, may be obtained free of charge, along with the Fund’s annual and semi-annual reports, by calling (800) 537-4942. The SAI, as amended and/or supplemented from time to time, is incorporated by reference into this prospectus.

BlackRock Investor Services
Representatives are available to discuss account balance information, mutual fund prospectuses, literature, programs and services available. Hours: 8:00 a.m. to 6:00 p.m. (Eastern time), on any business day. Call: (800) 537-4942.

Purchases and Redemptions
Call your Financial Intermediary or BlackRock Investor Services at (800) 537-4942.

World Wide Web
General Fund information and specific Fund performance, including the SAI and annual/semi-annual reports, can be accessed free of charge at www.blackrock.com/prospectus. Mutual fund prospectuses and literature can also be requested via this website.

Written Correspondence
BlackRock Bond Fund, Inc.
P.O. Box 9819
Providence, Rhode Island 02940

Overnight Mail
BlackRock Bond Fund, Inc.
4400 Computer Drive
Westborough, Massachusetts 01581

Internal Wholesalers/Broker Dealer Support
Available on any business day to support investment professionals. Call: (800) 882-0052.

Portfolio Characteristics and Holdings
A description of the Fund’s policies and procedures related to disclosure of portfolio characteristics and holdings is available in the SAI.

For information about portfolio holdings and characteristics, BlackRock fund shareholders and prospective investors may call (800) 882-0052.

Securities and Exchange Commission
You may also view and copy public information about the Fund, including the SAI, by visiting the EDGAR database on the SEC’s website (http://www.sec.gov). Copies of this information can be obtained, for a duplicating fee, by electronic request at the following e-mail address: publicinfo@sec.gov.

You should rely only on the information contained in this prospectus. No one is authorized to provide you with information that is different from information contained in this prospectus.

The SEC and the Commodity Futures Trading Commission have not approved or disapproved these securities or passed upon the adequacy of this prospectus. Any representation to the contrary is a criminal offense.

PRO-10046-K-0121

For More Information	Fund and Service Providers	Inside Back Cover
	Additional Information	Back Cover

Fund Overview	Key facts and details about the Fund listed in this prospectus, including investment objectives, principal investment strategies, principal risk factors, fee and expense information and historical performance information
	Investment Objective	3
	Fees and Expenses of the Fund	3
	Principal Investment Strategies of the Fund	4
	Principal Risks of Investing in the Fund	4
	Performance Information	8
	Investment Manager	9
	Portfolio Managers	9
	Purchase and Sale of Fund Shares	9
	Tax Information	10
	Payments to Broker/Dealers and Other Financial Intermediaries	10

Account Information	Information about account services, sales charges and waivers, shareholder transactions, and distributions and other payments
	Details About the Share Class	25
	How to Buy, Sell, Exchange and Transfer Shares	26
	Fund’s Rights	31
	Short-Term Trading Policy	31

Management of the Fund	Information about BlackRock and the Portfolio Managers
	BlackRock	33
	Portfolio Manager Information	35
	Conflicts of Interest	35
	Master/Feeder Structure	36
	Valuation of Fund Investments	37
	Dividends, Distributions and Taxes	38