0000276463 2012-01-29 2013-01-28 0000276463 bbfi5:S000004071Member bbfi5:InvestorInstitutionalAndRsharesMember 2012-01-29 2013-01-28 0000276463 bbfi5:S000004071Member bbfi5:InvestorInstitutionalAndRsharesMember bbfi5:C000011387Member 2012-01-29 2013-01-28 0000276463 bbfi5:S000004071Member bbfi5:InvestorInstitutionalAndRsharesMember bbfi5:C000011388Member 2012-01-29 2013-01-28 0000276463 bbfi5:S000004071Member bbfi5:InvestorInstitutionalAndRsharesMember bbfi5:C000037620Member 2012-01-29 2013-01-28 0000276463 bbfi5:S000004071Member bbfi5:InvestorInstitutionalAndRsharesMember bbfi5:C000011390Member 2012-01-29 2013-01-28 0000276463 bbfi5:S000004071Member bbfi5:InvestorInstitutionalAndRsharesMember bbfi5:C000011391Member 2012-01-29 2013-01-28 0000276463 bbfi5:S000004071Member bbfi5:ServiceSharesMember bbfi5:C000052630Member 2012-01-29 2013-01-28 0000276463 bbfi5:S000004071Member bbfi5:BlackrockSharesMember bbfi5:C000052631Member 2012-01-29 2013-01-28 0000276463 bbfi5:S000004071Member bbfi5:ServiceSharesMember 2012-01-29 2013-01-28 0000276463 bbfi5:S000004071Member bbfi5:PrimeSharesMember 2012-01-29 2013-01-28 0000276463 bbfi5:S000004071Member bbfi5:ServiceSharesMember rr:AfterTaxesOnDistributionsMember bbfi5:C000052630Member 2012-01-29 2013-01-28 0000276463 bbfi5:S000004071Member bbfi5:ServiceSharesMember rr:AfterTaxesOnDistributionsAndSalesMember bbfi5:C000052630Member 2012-01-29 2013-01-28 0000276463 bbfi5:S000004071Member bbfi5:ServiceSharesMember bbfi5:BarclaysUsAggregateBondIndexMember 2012-01-29 2013-01-28 0000276463 bbfi5:S000004071Member bbfi5:BlackrockSharesMember 2012-01-29 2013-01-28 0000276463 bbfi5:S000004071Member bbfi5:InvestorInstitutionalAndRsharesMember rr:AfterTaxesOnDistributionsMember bbfi5:C000011387Member 2012-01-29 2013-01-28 0000276463 bbfi5:S000004071Member bbfi5:InvestorInstitutionalAndRsharesMember rr:AfterTaxesOnDistributionsAndSalesMember bbfi5:C000011387Member 2012-01-29 2013-01-28 0000276463 bbfi5:S000004071Member bbfi5:InvestorInstitutionalAndRsharesMember bbfi5:BarclaysUsAggregateBondIndexMember 2012-01-29 2013-01-28 0000276463 bbfi5:S000004071Member bbfi5:BlackrockSharesMember rr:AfterTaxesOnDistributionsMember bbfi5:C000052631Member 2012-01-29 2013-01-28 0000276463 bbfi5:S000004071Member bbfi5:BlackrockSharesMember rr:AfterTaxesOnDistributionsAndSalesMember bbfi5:C000052631Member 2012-01-29 2013-01-28 0000276463 bbfi5:S000004071Member bbfi5:BlackrockSharesMember bbfi5:BarclaysUsAggregateBondIndexMember 2012-01-29 2013-01-28 0000276463 bbfi5:S000004071Member bbfi5:PrimeSharesMember bbfi5:C000011389Member 2012-01-29 2013-01-28 0000276463 bbfi5:S000004071Member bbfi5:PrimeSharesMember bbfi5:C000037618Member 2012-01-29 2013-01-28 0000276463 bbfi5:S000004071Member bbfi5:PrimeSharesMember bbfi5:C000037619Member 2012-01-29 2013-01-28 0000276463 bbfi5:S000004071Member bbfi5:PrimeSharesMember bbfi5:C000052629Member 2012-01-29 2013-01-28 0000276463 bbfi5:S000004071Member bbfi5:PrimeSharesMember bbfi5:C000037621Member 2012-01-29 2013-01-28 0000276463 bbfi5:S000004071Member bbfi5:PrimeSharesMember rr:AfterTaxesOnDistributionsMember bbfi5:C000011389Member 2012-01-29 2013-01-28 0000276463 bbfi5:S000004071Member bbfi5:PrimeSharesMember rr:AfterTaxesOnDistributionsAndSalesMember bbfi5:C000011389Member 2012-01-29 2013-01-28 0000276463 bbfi5:S000004071Member bbfi5:PrimeSharesMember bbfi5:BarclaysUsAggregateBondIndexMember 2012-01-29 2013-01-28 pure iso4217:USD 2013-01-28 485BPOS BLACKROCK BOND FUND, INC. 0000276463 2013-01-28 2013-01-28 false 2012-09-30 The investment objective of the BlackRock Total Return Fund (the “Fund”) is to realize a total return that exceeds that of the Barclays U.S. Aggregate Bond Index. This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $25,000 in the BlackRock-advised fund complex. More information about these and other discounts is available from your financial professional and in the “Details about the Share Classes” section on page 25 of the Fund’s prospectus and in the “Purchase of Shares” section on page II-71 of the Fund’s statement of additional information. 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: 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 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 1,346% of the average value of its portfolio. Example: 0.04 0 0 0 0 0 0.04 0.01 0 0 0.0045 0.0045 0.0045 0.0045 0.0045 0.0025 0.0075 0.01 0 0.005 0.0042 0.0066 0.0043 0.0037 0.0051 0.0017 0.0017 0.0017 0.0017 0.0017 0.0025 0.0049 0.0026 0.002 0.0034 0.0112 0.0186 0.0188 0.0082 0.0146 0.0105 0.0179 0.0181 0.0072 0.0127 -0.0007 -0.0007 -0.0007 -0.001 -0.0019 Shareholder Fees (fees paid directly from your investment) Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment) 0.0045 0.0045 0.0025 0.0048 0.0017 0 0.0023 0.0031 0.0118 -0.0016 0.0102 0.0068 -0.0011 0.0057 58 191 336 758 0.047 0.0452 0.0252 0.0425 0.0526 -0.111 0.1636 0.1014 0.0468 0.1027 The investment objective of the BlackRock Total Return Fund (the “Fund”) is to realize a total return that exceeds that of the Barclays U.S. Aggregate Bond Index. 503 582 284 74 129 721 863 569 237 428 <a name="e50915_3toc1"></a>Investment Objective The investment objective of the BlackRock Total Return Fund (the “Fund”) is to realize a total return that exceeds that of the Barclays U.S. Aggregate Bond Index. <a name="e50915_3toc2"></a>Fees and Expenses of the Fund This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. 956 1170 980 414 749 1631 2105 2127 928 1658 104 344 603 1344 182 184 563 569 970 980 2105 2127 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: 0.0421 0.0395 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 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 1,346% of the average value of its portfolio. 0.0203 0.0368 0.0482 -0.1141 0.1595 0.0975 0.043 0.0988 0.0424 0.0406 0.0207 0.0379 0.0477 -0.1152 0.1584 0.097 <a name="e50915_3toc4"></a>Principal Risks of Investing in the Fund 0.043 0.097 0.0847 0.0988 0.0638 0.0421 0.0526 0.036 0.0348 0.0595 0.0449 0.0362 0.0336 0.0518 The investment objective of the BlackRock Total Return Fund (the “Fund”) is to realize a total return that exceeds that of the Barclays U.S. Aggregate Bond Index. 0.0531 This table describes the fees and expenses that you may pay if you buy and hold BlackRock Shares of the Fund. 0.0399 0.0342 0.049 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:  0.0803 0.1014 0.0944 0.0421 The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover 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 1,346% of the average value of its portfolio. 0.0431 0.027 0.0269 0.0411 0.0452 0.0549 0.049 0.0595 0.0405 0.0241 0.0246 0.0385 0.0377 0.0479 0.0423 0.0518 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 Barclays U.S. Aggregate Bond Index. Effective September 24, 2007, the Fund reorganized with BlackRock Total Return Portfolio (the “Predecessor Fund”), a series of BlackRock Funds II (the “Reorganization”), and the Predecessor Fund’s performance and financial history has been adopted by the Fund and will be used going forward from the date of the Reorganization. The information below is based on the performance information of the combined fund resulting from the Reorganization and that of the Predecessor Fund prior to the Reorganization. Prior to September 24, 2007, BlackRock Share performance results are those of BlackRock Shares of the Predecessor Fund with no adjustments. As with all such investments, past performance (before and after taxes) is not an indication of future results. Sales charges are not reflected in the bar chart. If they were, returns would be less than those shown. However, the table includes all applicable fees and sales charges. 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 can be obtained by visiting http://www.blackrock.com/funds or can be obtained by phone at 800-882-0052. 0.0017 0.0006 0.1027 0.0873 0.0664 0.0421 0.0563 0.0384 0.0372 0.0595 0.0494 0.032 0.0317 0.0518 This table describes the fees and expenses that you may pay if you buy and hold Service Shares of the Fund. <a name="e50915_3toc5"></a>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 Barclays U.S. Aggregate Bond Index. Effective September 24, 2007, the Fund reorganized with BlackRock Total Return Portfolio (the “Predecessor Fund”), a series of BlackRock Funds II (the “Reorganization”), and the Predecessor Fund’s performance and financial history has been adopted by the Fund and will be used going forward from the date of the Reorganization. The information below is based on the performance information of the combined fund resulting from the Reorganization and that of the Predecessor Fund prior to the Reorganization (adjusted as necessary to reflect the fees applicable to each class of shares). Prior to September 24, 2007, Investor A1, Investor B1, Investor C1 and Investor C2 Share performance results are those of BlackRock Shares of the Predecessor Fund restated to reflect Investor A1, Investor B1, Investor C1 and Investor C2 fees, respectively. Prior to September 24, 2007, Investor B2 Share performance results are those of Investor B Shares of the Predecessor Fund with no adjustments. As with all such investments, past performance (before and after taxes) is not an indication of future results. Sales charges are not reflected in the bar chart. If they were, returns would be less than those shown. However, the table includes all applicable fees and sales charges. 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 can be obtained by visiting http://www.blackrock.com/funds or can be obtained by phone at 800-882-0052. <a name="e50915_1toc2"></a>Fees and Expenses of the Fund During the ten-year period shown in the bar chart, the highest return for a quarter was 6.86% (quarter ended September 30, 2009) and the lowest return for a quarter was –7.03% (quarter ended September 30, 2008). <div style="display:none">~ http://www.blackrock.com/role/ScheduleAnnualFundOperatingExpensesBlackRockTotalReturnFundServiceShares column period compact * ~</div> <a name="e50915_1toc3"></a>Principal Investment Strategies of the Fund <div style="display:none">~ http://www.blackrock.com/role/ScheduleExpenseExampleTransposedBlackRockTotalReturnFundServiceShares column period compact * ~</div> <a name="e50915_1toc4"></a>Principal Risks of Investing in the Fund <div style="display:none">~ http://www.blackrock.com/role/ScheduleAnnualTotalReturnsBlackRockTotalReturnFundServiceSharesBarChart column period compact * ~</div> <a name="e50915_1toc5"></a>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 Barclays U.S. Aggregate Bond Index. Effective September 24, 2007, the Fund reorganized with BlackRock Total Return Portfolio (the “Predecessor Fund”), a series of BlackRock Funds II (the “Reorganization”), and the Predecessor Fund’s performance and financial history has been adopted by the Fund and will be used going forward from the date of the Reorganization. The information below is based on the performance information of the combined fund resulting from the Reorganization and that of the Predecessor Fund prior to the Reorganization (adjusted as necessary to reflect the fees applicable to each class of shares). Prior to September 24, 2007, Investor A, Investor B and Institutional Share performance results are those of BlackRock Shares of the Predecessor Fund restated to reflect Investor A, Investor B and Institutional Share fees, respectively. Prior to September 24, 2007, Investor C Share performance results are those of Investor C Shares of a predecessor fund with no adjustments. Prior to October 2, 2006, Class R Share performance results are those of the Class R Shares of the Predecessor Fund. Prior to the Predecessor Fund Class R Shares inception date, the Class R Share performance is based on the performance of the BlackRock Shares of the Predecessor Fund restated to reflect Class R Share fees. As with all such investments, past performance (before and after taxes) is not an indication of future results. Sales charges are not reflected in the bar chart. If they were, returns would be less than those shown. However, the table includes all applicable fees and sales charges. 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 can be obtained by visiting http://www.blackrock.com/funds or can be obtained by phone at 800-882-0052. 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: The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover 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 1,346% of the average value of its portfolio. During the ten-year period shown in the bar chart, the highest return for a quarter was 7.12% (quarter ended September 30, 2009) and the lowest return for a quarter was –6.97% (quarter ended September 30, 2008). Fund Overview Key Facts about BlackRock Total Return Fund Investment Objective Fees and Expenses of the Fund Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment) Portfolio Turnover: Example: Principal Investment Strategies of the Fund Principal Risks of Investing in the Fund Performance Information Service Shares ANNUAL TOTAL RETURNS BlackRock Total Return Fund As of 12/31 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. After-tax returns are shown for Investor A Shares only, and the after-tax returns for Investor B, Investor C, Institutional and Class R Shares will vary. During the ten-year period shown in the bar chart, the highest return for a quarter was 7.15% (quarter ended September 30, 2009) and the lowest return for a quarter was –6.93% (quarter ended September 30, 2008). As of 12/31/12 Average Annual Total Returns 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 dollar rolls. The Fund may invest up to 20% of its net assets in fixed-income securities that are rated below investment grade by at least one of the recognized rating agencies or in unrated securities of equivalent credit quality. The Fund is a “feeder” fund that invests all of its assets in a corresponding “master” portfolio, the Master Total Return Portfolio (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 exchange traded funds, which are designed to provide this exposure without direct investment in physical commodities. The Fund may also gain exposure to commodity markets by investing, through the Master Portfolio, up to 25% of its total assets in the Subsidiary, a wholly owned subsidiary of the Master Portfolio formed in the Cayman Islands, which invests primarily in commodity-related instruments. 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 Barclays U.S. Aggregate Bond Index. Effective September 24, 2007, the Fund reorganized with BlackRock Total Return Portfolio (the “Predecessor Fund”), a series of BlackRock Funds II (the “Reorganization”), and the Predecessor Fund’s performance and financial history has been adopted by the Fund and will be used going forward from the date of the Reorganization. The information below is based on the performance information of the combined fund resulting from the Reorganization and that of the Predecessor Fund prior to the Reorganization (adjusted as necessary to reflect the fees applicable to Service Shares of the Fund). Prior to September 24, 2007, Service Share performance results are those of Investor A Shares of the Predecessor Fund restated to reflect Service Share fees. As with all such investments, past performance (before and after taxes) is not an indication of future results. Sales charges are not reflected in the bar chart. If they were, returns would be less than those shown. However, the table includes all applicable fees and sales charges. 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 can be obtained by visiting http://www.blackrock.com/funds or can be obtained by phone at 800-882-0052. 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. Fund Overview Key Facts about BlackRock Total Return Fund Investment Objective Fees and Expenses of the Fund <div style="display:none">~ http://www.blackrock.com/role/ScheduleAverageAnnualTotalReturnsTransposedBlackRockTotalReturnFundServiceShares column period compact * ~</div> 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. After-tax returns are shown for Investor C1 Shares only, and the after-tax returns for Investor A1, Investor B1, Investor B2 and Investor C2 Shares will vary. Shareholder Fees (fees paid directly from your investment) Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment) <a name="e50915_3toc3"></a>Principal Investment Strategies of the Fund Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment) Portfolio Turnover: 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 dollar rolls. The Fund may invest up to 20% of its net assets in fixed-income securities that are rated below investment grade by at least one of the recognized rating agencies or in unrated securities of equivalent credit quality. The Fund is a “feeder” fund that invests all of its assets in a corresponding “master” portfolio, the Master Total Return Portfolio (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 exchange traded funds, which are designed to provide this exposure without direct investment in physical commodities. The Fund may also gain exposure to commodity markets by investing, through the Master Portfolio, up to 25% of its total assets in the Subsidiary, a wholly owned subsidiary of the Master Portfolio formed in the Cayman Islands, which invests primarily in commodity-related instruments. Example: Principal Investment Strategies of the Fund You would pay the following expenses if you did not redeem your shares: Principal Risks of Investing in 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 dollar rolls. The Fund may invest up to 20% of its net assets in fixed-income securities that are rated below investment grade by at least one of the recognized rating agencies or in unrated securities of equivalent credit quality. The Fund is a “feeder” fund that invests all of its assets in a corresponding “master” portfolio, the Master Total Return Portfolio (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 exchange traded funds, which are designed to provide this exposure without direct investment in physical commodities. The Fund may also gain exposure to commodity markets by investing, through the Master Portfolio, up to 25% of its total assets in the Subsidiary, a wholly owned subsidiary of the Master Portfolio formed in the Cayman Islands, which invests primarily in commodity-related instruments. Performance Information 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 dollar rolls. The Fund may invest up to 20% of its net assets in fixed-income securities that are rated below investment grade by at least one of the recognized rating agencies or in unrated securities of equivalent credit quality. The Fund is a “feeder” fund that invests all of its assets in a corresponding “master” portfolio, the Master Total Return Portfolio (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 exchange traded funds, which are designed to provide this exposure without direct investment in physical commodities. The Fund may also gain exposure to commodity markets by investing, through the Master Portfolio, up to 25% of its total assets in the Subsidiary, a wholly owned subsidiary of the Master Portfolio formed in the Cayman Islands, which invests primarily in commodity-related instruments. Investor C1 Shares ANNUAL TOTAL RETURNS BlackRock Total Return Fund As of 12/31 You would pay the following expenses if you did not redeem your shares: BlackRock 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 7.13% (quarter ended September 30, 2009) and the lowest return for a quarter was –6.85% (quarter ended September 30, 2008). Investor A Shares ANNUAL TOTAL RETURNS BlackRock Total Return Fund As of 12/31 As of 12/31/12 Average Annual Total Returns As of 12/31/12 Average Annual Total Returns 13.46 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. 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 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. 800-882-0052 February 1, 2014 http://www.blackrock.com/funds As with all such investments, past performance (before and after taxes) is not an indication of future results. 13.46 Sales charges are not reflected in the bar chart. If they were, returns would be less than those shown. 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 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. 800-882-0052 February 1, 2014 http://www.blackrock.com/funds February 1, 2014 13.46 13.46 As with all such investments, past performance (before and after taxes) is not an indication of future results. You may lose part or all of your investment in the Fund or your investment may not perform as well as other similar investments. Sales charges are not reflected in the bar chart. If they were, returns would be less than those shown. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $25,000 in the BlackRock-advised fund complex. 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. 25000 However, the table includes all applicable fees and sales charges. 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. You may lose part or all of your investment in the Fund or your investment may not perform as well as other similar investments. 800-882-0052 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. http://www.blackrock.com/funds 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. As with all such investments, past performance (before and after taxes) is not an indication of future results. highest return Sales charges are not reflected in the bar chart. If they were, returns would be less than those shown. 2009-09-30 800-882-0052 0.0713 http://www.blackrock.com/funds As of 12/31/12 Average Annual Total Returns 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. lowest return As with all such investments, past performance (before and after taxes) is not an indication of future results. 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. 2008-09-30 Sales charges are not reflected in the bar chart. If they were, returns would be less than those shown. -0.0685 However, the table includes all applicable fees and sales charges. However, the table includes all applicable fees and sales charges. highest return However, the table includes all applicable fees and sales charges. 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. 2009-09-30 0.0715 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. lowest return 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. After-tax returns are shown for Investor C1 Shares only, and the after-tax returns for Investor A1, Investor B1, Investor B2 and Investor C2 Shares will vary. 2008-09-30 After-tax returns are shown for Investor A Shares only, and the after-tax returns for Investor B, Investor C, Institutional and Class R Shares will vary. -0.0693 highest return 2009-09-30 0.0686 lowest return 2008-09-30 -0.0703 Fund Overview Key Facts about BlackRock Total Return Fund <div style="display:none">~ http://www.blackrock.com/role/ScheduleAnnualFundOperatingExpensesBlackRockTotalReturnFundBlackRockShares column period compact * ~</div> <div style="display:none">~ http://www.blackrock.com/role/ScheduleExpenseExampleTransposedBlackRockTotalReturnFundBlackRockShares column period compact * ~</div> 0.0367 0.0349 0.0152 0.0322 0.042 -0.1204 0.1517 0.0911 0.0362 0.0917 <div style="display:none">~ http://www.blackrock.com/role/ScheduleAnnualTotalReturnsBlackRockTotalReturnFundBlackRockSharesBarChart column period compact * ~</div> 0.01 0 0 0 0 highest return 0 2009-09-30 0.0712 lowest return 2008-09-30 <div style="display:none">~ http://www.blackrock.com/role/ScheduleAverageAnnualTotalReturnsTransposedBlackRockTotalReturnFundBlackRockShares column period compact * ~</div> -0.0697 0.01 0.045 0.01 0.01 0.0045 0.0045 0.0045 0.0045 0.0045 0.001 0.005 0.008 0.005 0.0039 0.0054 0.0161 0.0045 0.0053 0.0017 0.0017 0.0017 0.0017 0.0017 0.0022 0.0037 0.0144 0.0028 0.0036 0.0094 0.0149 0.0306 0.017 0.0148 0.0087 0.0142 0.0182 0.0163 0.0141 -0.0007 -0.0007 -0.0124 -0.0007 -0.0007 0.01 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.<ul type="square"><li style="margin-left:-20px">Commodities Related Investments Risks — 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 sectors affecting a particular industry or commodity, such as drought, floods, weather, embargoes, tariffs and international economic, political and regulatory developments.</li></ul><ul type="square"><li style="margin-left:-20px">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.</li></ul><ul type="square"><li style="margin-left:-20px">Credit Risk — Credit risk refers to the possibility that the issuer of a security 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.</li></ul><ul type="square"><li style="margin-left:-20px">Derivatives 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. Derivatives are also subject to counterparty risk, which is the risk that the other party in the transaction will not fulfill its contractual obligation. A risk of the Fund’s use of derivatives is that the fluctuations in their values may not correlate perfectly with the overall securities markets. 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. Derivatives may give rise to a form of leverage and may expose the Fund to greater risk and increase its costs. Recent legislation calls for new regulation of the derivatives markets. The extent and impact of the regulation is not yet known and may not be known for some time. New regulation may make derivatives more costly, may limit the availability of derivatives, or may otherwise adversely affect the value or performance of derivatives.</li></ul><ul type="square"><li style="margin-left:-20px">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.</li></ul><ul type="square"><li style="margin-left:-20px">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.</li></ul><ul type="square"><li style="margin-left:-20px">Extension Risk — When interest rates rise, certain obligations will be paid off by the obligor more slowly than anticipated, causing the value of these securities to fall.</li></ul><ul type="square"><li style="margin-left:-20px">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:</li></ul><blockquote><ul type="square"><li style="margin-left:-20px"> 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.</li></ul></blockquote><blockquote><ul type="square"><li style="margin-left:-20px">Changes in foreign currency exchange rates can affect the value of the Fund’s portfolio.</li></ul></blockquote><blockquote><ul type="square"><li style="margin-left:-20px">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.</li></ul></blockquote><blockquote><ul type="square"><li style="margin-left:-20px">The governments of certain countries may prohibit or impose substantial restrictions on foreign investments in their capital markets or in certain industries.</li></ul></blockquote><blockquote><ul type="square"><li style="margin-left:-20px">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.</li></ul></blockquote><blockquote><ul type="square"><li style="margin-left:-20px">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.</li></ul></blockquote><ul type="square"><li style="margin-left:-20px">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 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.</li></ul><ul type="square"><li style="margin-left:-20px">Interest Rate Risk — 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.</li></ul><ul type="square"><li style="margin-left:-20px">Junk Bonds Risk — Although junk bonds generally pay higher rates of interest than investment grade bonds, junk bonds are high risk investments that may cause income and principal losses for the Fund.</li></ul><ul type="square"><li style="margin-left:-20px">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.</li></ul><ul type="square"><li style="margin-left:-20px">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. 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.</li></ul><ul type="square"><li style="margin-left:-20px">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 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.</li></ul><ul type="square"><li style="margin-left:-20px">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 stock of larger companies.</li></ul><ul type="square"><li style="margin-left:-20px">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.</li></ul><ul type="square"><li style="margin-left:-20px">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 securities. These events could also trigger adverse tax consequences to the Fund.</li></ul><ul type="square"><li style="margin-left:-20px">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.</li></ul><ul type="square"><li style="margin-left:-20px">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.</li></ul><ul type="square"><li style="margin-left:-20px">Subsidiary Risk — By indirectly investing in the Subsidiary through its investment in the Master Portfolio, the Fund is indirectly exposed to the risks associated with the Subsidiary’s investments. The commodity-related instruments held by the Subsidiary are generally similar to those that are permitted to be held by the Fund or the Master Portfolio and are subject to the same risks that apply to similar investments if held directly by the Fund or the Master Portfolio (see “Commodities Related Investment Risks” above). There can be no assurance that the investment objective of the Subsidiary will be achieved. The Subsidiary is not registered under the Investment Company Act, and, unless otherwise noted in this prospectus, is not subject to all the investor protections of the Investment Company Act. However, the Master Portfolio wholly owns and controls the Subsidiary, and the Master Portfolio and the Subsidiary are both managed by BlackRock, making it unlikely that the Subsidiary will take action contrary to the interests of the Fund and its shareholders. Changes in the laws of the United States and/or the Cayman Islands could result in the inability of the Fund and/or the Subsidiary to operate as described in this prospectus and the Statement of Additional Information (“SAI”) and could adversely affect the Fund.</li></ul><ul type="square"><li style="margin-left:-20px">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.</li></ul> 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.<ul type="square"><li style="margin-left: -20px">Commodities Related Investments Risks — 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 sectors affecting a particular industry or commodity, such as drought, floods, weather, embargoes, tariffs and international economic, political and regulatory developments.</li></ul><ul type="square"><li style="margin-left: -20px">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.</li></ul><ul type="square"><li style="margin-left: -20px">Credit Risk — Credit risk refers to the possibility that the issuer of a security 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.</li></ul><ul type="square"><li style="margin-left: -20px">Derivatives 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. Derivatives are also subject to counterparty risk, which is the risk that the other party in the transaction will not fulfill its contractual obligation. A risk of the Fund’s use of derivatives is that the fluctuations in their values may not correlate perfectly with the overall securities markets. 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. Derivatives may give rise to a form of leverage and may expose the Fund to greater risk and increase its costs. Recent legislation calls for new regulation of the derivatives markets. The extent and impact of the regulation is not yet known and may not be known for some time. New regulation may make derivatives more costly, may limit the availability of derivatives, or may otherwise adversely affect the value or performance of derivatives.</li></ul><ul type="square"><li style="margin-left: -20px">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.</li></ul><ul type="square"><li style="margin-left: -20px">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.</li></ul><ul type="square"><li style="margin-left: -20px">Extension Risk — When interest rates rise, certain obligations will be paid off by the obligor more slowly than anticipated, causing the value of these securities to fall.</li></ul><ul type="square"><li style="margin-left: -20px">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:</li></ul><blockquote><ul type="square"><li style="margin-left: -20px">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.</li></ul><ul type="square"><li style="margin-left: -20px">Changes in foreign currency exchange rates can affect the value of the Fund’s portfolio.</li></ul><ul type="square"><li style="margin-left: -20px">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.</li></ul><ul type="square"><li style="margin-left: -20px">The governments of certain countries may prohibit or impose substantial restrictions on foreign investments in their capital markets or in certain industries.</li></ul><ul type="square"><li style="margin-left: -20px">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.</li></ul><ul type="square"><li style="margin-left: -20px">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.</li></ul></blockquote><ul type="square"><li style="margin-left: -20px">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 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.</li></ul><ul type="square"><li style="margin-left: -20px">Interest Rate Risk — 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.</li></ul><ul type="square"><li style="margin-left: -20px">Junk Bonds Risk — Although junk bonds generally pay higher rates of interest than investment grade bonds, junk bonds are high risk investments that may cause income and principal losses for the Fund.</li></ul><ul type="square"><li style="margin-left: -20px">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.</li></ul><ul type="square"><li style="margin-left: -20px">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. 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.</li></ul><ul type="square"><li style="margin-left: -20px">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 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.</li></ul><ul type="square"><li style="margin-left: -20px">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 stock of larger companies.</li></ul><ul type="square"><li style="margin-left: -20px">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.</li></ul><ul type="square"><li style="margin-left: -20px">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 securities. These events could also trigger adverse tax consequences to the Fund.</li></ul><ul type="square"><li style="margin-left: -20px">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.</li></ul><ul type="square"><li style="margin-left: -20px">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.</li></ul><ul type="square"><li style="margin-left: -20px">Subsidiary Risk — By indirectly investing in the Subsidiary through its investments in the Master Portfolio, the Fund is indirectly exposed to the risks associated with the Subsidiary’s investments. The commodity-related instruments held by the Subsidiary are generally similar to those that are permitted to be held by the Fund or the Master Portfolio and are subject to the same risks that apply to similar investments if held directly by the Fund or the Master Portfolio (see “Commodities Related Investment Risks” above). There can be no assurance that the investment objective of the Subsidiary will be achieved. The Subsidiary is not registered under the Investment Company Act, and, unless otherwise noted in this prospectus, is not subject to all the investor protections of the Investment Company Act. However, the Master Portfolio wholly owns and controls the Subsidiary, and the Master Portfolio and the Subsidiary are both managed by BlackRock, making it unlikely that the Subsidiary will take action contrary to the interests of the Fund and its shareholders. Changes in the laws of the United States and/or the Cayman Islands could result in the inability of the Fund and/or the Subsidiary to operate as described in this prospectus and the Statement of Additional Information (“SAI”) and could adversely affect the Fund.</li></ul><ul type="square"><li style="margin-left: -20px">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.</li></ul> 188 245 266 635 244 375 474 1164 514 446 577 776 1669 887 771 1162 1702 2539 1933 1691 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. <ul type="square"><li style="margin-left:-20px">Commodities Related Investments Risks — 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 sectors affecting a particular industry or commodity, such as drought, floods, weather, embargoes, tariffs and international economic, political and regulatory developments.</li></ul> <ul type="square"><li style="margin-left:-20px">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.</li></ul> <ul type="square"><li style="margin-left:-20px">Credit Risk — Credit risk refers to the possibility that the issuer of a security 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.</li></ul> <ul type="square"><li style="margin-left:-20px">Derivatives 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. Derivatives are also subject to counterparty risk, which is the risk that the other party in the transaction will not fulfill its contractual obligation. A risk of the Fund’s use of derivatives is that the fluctuations in their values may not correlate perfectly with the overall securities markets. 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. Derivatives may give rise to a form of leverage and may expose the Fund to greater risk and increase its costs. Recent legislation calls for new regulation of the derivatives markets. The extent and impact of the regulation is not yet known and may not be known for some time. New regulation may make derivatives more costly, may limit the availability of derivatives, or may otherwise adversely affect the value or performance of derivatives.</li></ul> <ul type="square"><li style="margin-left:-20px">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.</li></ul> <ul type="square"><li style="margin-left:-20px">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.</li></ul> <ul type="square"><li style="margin-left:-20px">Extension Risk — When interest rates rise, certain obligations will be paid off by the obligor more slowly than anticipated, causing the value of these securities to fall.</li></ul> <ul type="square"><li style="margin-left:-20px">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:</li></ul> <blockquote><ul type="square"><li style="margin-left:-20px">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.</li></ul></blockquote> <blockquote><ul type="square"><li style="margin-left:-20px">Changes in foreign currency exchange rates can affect the value of the Fund’s portfolio. </li></ul></blockquote><blockquote><ul type="square"><li style="margin-left:-20px"> 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.</li></ul></blockquote> <blockquote><ul type="square"><li style="margin-left:-20px">The governments of certain countries may prohibit or impose substantial restrictions on foreign investments in their capital markets or in certain industries.</li></ul></blockquote> <blockquote><ul type="square"><li style="margin-left:-20px">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.</li></ul></blockquote> <blockquote><ul type="square"><li style="margin-left:-20px">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.</li></ul></blockquote> <ul type="square"><li style="margin-left:-20px">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 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.</li></ul> <ul type="square"><li style="margin-left:-20px">Interest Rate Risk — 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.</li></ul> <ul type="square"><li style="margin-left:-20px">Junk Bonds Risk — Although junk bonds generally pay higher rates of interest than investment grade bonds, junk bonds are high risk investments that may cause income and principal losses for the Fund.</li></ul> <ul type="square"><li style="margin-left:-20px">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.</li></ul> <ul type="square"><li style="margin-left:-20px">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. 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.</li></ul> <ul type="square"><li style="margin-left:-20px">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 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.</li></ul> <ul type="square"><li style="margin-left:-20px">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 stock of larger companies.</li></ul> <ul type="square"><li style="margin-left:-20px">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.</li></ul> <ul type="square"><li style="margin-left:-20px">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 securities. These events could also trigger adverse tax consequences to the Fund. </li></ul> <ul type="square"><li style="margin-left:-20px">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.</li></ul> <ul type="square"><li style="margin-left:-20px">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.</li></ul> <ul type="square"><li style="margin-left:-20px">Subsidiary Risk — By indirectly investing in the Subsidiary through its investment in the Master Portfolio, the Fund is indirectly exposed to the risks associated with the Subsidiary’s investments. The commodity-related instruments held by the Subsidiary are generally similar to those that are permitted to be held by the Fund or the Master Portfolio and are subject to the same risks that apply to similar investments if held directly by the Fund or the Master Portfolio (see “Commodities Related Investment Risks” above). There can be no assurance that the investment objective of the Subsidiary will be achieved. The Subsidiary is not registered under the Investment Company Act, and, unless otherwise noted in this prospectus, is not subject to all the investor protections of the Investment Company Act. However, the Master Portfolio wholly owns and controls the Subsidiary, and the Master Portfolio and the Subsidiary are both managed by BlackRock, making it unlikely that the Subsidiary will take action contrary to the interests of the Fund and its shareholders. Changes in the laws of the United States and/or the Cayman Islands could result in the inability of the Fund and/or the Subsidiary to operate as described in this prospectus and the Statement of Additional Information (“SAI”) and could adversely affect the Fund.</li></ul> <ul type="square"><li style="margin-left:-20px">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.</li></ul> 145 185 144 166 514 814 446 1469 887 771 2539 1933 1691 <div style="display:none">~ http://www.blackrock.com/role/ScheduleShareholderFeesBlackRockTotalReturnFund column period compact * ~</div> 449 776 1702 <div style="display:none">~ http://www.blackrock.com/role/ScheduleAnnualFundOperatingExpensesBlackRockTotalReturnFund column period compact * ~</div> <div style="display:none">~ http://www.blackrock.com/role/ScheduleExpenseExampleTransposedBlackRockTotalReturnFund column period compact * ~</div> 0.0817 0.0702 0.0529 0.0882 0.0841 0.0582 0.0843 0.0421 0.0457 0.0316 0.0305 0.051 <div style="display:none">~ http://www.blackrock.com/role/ScheduleExpenseExampleNoRedemptionTransposedBlackRockTotalReturnFund column period compact * ~</div> 0.0479 0.0504 0.0476 0.0595 0.0389 0.0236 0.024 0.0453 0.0416 0.0416 0.0414 0.0518 <div style="display:none">~ http://www.blackrock.com/role/ScheduleAnnualTotalReturnsBlackRockTotalReturnFundBarChart column period compact * ~</div> <div style="display:none">~ http://www.blackrock.com/role/ScheduleAverageAnnualTotalReturnsTransposedBlackRockTotalReturnFund column period compact * ~</div> Investment Objective 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.<ul type="square"><li style="margin-left:-20px">Commodities Related Investments Risks — 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 sectors affecting a particular industry or commodity, such as drought, floods, weather, embargoes, tariffs and international economic, political and regulatory developments.</li></ul> <ul type="square"><li style="margin-left:-20px">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.</li></ul> <ul type="square"><li style="margin-left:-20px">Credit Risk — Credit risk refers to the possibility that the issuer of a security 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.</li></ul> <ul type="square"><li style="margin-left:-20px">Derivatives 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. Derivatives are also subject to counterparty risk, which is the risk that the other party in the transaction will not fulfill its contractual obligation. A risk of the Fund’s use of derivatives is that the fluctuations in their values may not correlate perfectly with the overall securities markets. 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. Derivatives may give rise to a form of leverage and may expose the Fund to greater risk and increase its costs. Recent legislation calls for new regulation of the derivatives markets. The extent and impact of the regulation is not yet known and may not be known for some time. New regulation may make derivatives more costly, may limit the availability of derivatives, or may otherwise adversely affect the value or performance of derivatives.</li></ul> <ul type="square"><li style="margin-left:-20px">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.</li></ul> <ul type="square"><li style="margin-left:-20px">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.</li></ul> <ul type="square"><li style="margin-left:-20px">Extension Risk — When interest rates rise, certain obligations will be paid off by the obligor more slowly than anticipated, causing the value of these securities to fall.</li></ul> <ul type="square"><li style="margin-left:-20px">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:</li></ul> <blockquote><ul type="square"><li style="margin-left:-20px"> 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.</li></ul></blockquote> <blockquote><ul type="square"><li style="margin-left:-20px"> Changes in foreign currency exchange rates can affect the value of the Fund’s portfolio.</li></ul></blockquote> <blockquote><ul type="square"><li style="margin-left:-20px"> 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.</li></ul></blockquote> <blockquote><ul type="square"><li style="margin-left:-20px"> The governments of certain countries may prohibit or impose substantial restrictions on foreign investments in their capital markets or in certain industries.</li></ul></blockquote> <blockquote><ul type="square"><li style="margin-left:-20px"> 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.</li></ul></blockquote> <blockquote><ul type="square"><li style="margin-left:-20px"> 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.</li></ul></blockquote> <ul type="square"><li style="margin-left:-20px">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 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.</li></ul> <ul type="square"><li style="margin-left:-20px">Interest Rate Risk — 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.</li></ul> <ul type="square"><li style="margin-left:-20px">Junk Bonds Risk — Although junk bonds generally pay higher rates of interest than investment grade bonds, junk bonds are high risk investments that may cause income and principal losses for the Fund.</li></ul> <ul type="square"><li style="margin-left:-20px">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.</li></ul> <ul type="square"><li style="margin-left:-20px">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. 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.</li></ul> <ul type="square"><li style="margin-left:-20px">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 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.</li></ul> <ul type="square"><li style="margin-left:-20px">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 stock of larger companies. </li></ul> <ul type="square"><li style="margin-left:-20px">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.</li></ul> <ul type="square"><li style="margin-left:-20px">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 securities. These events could also trigger adverse tax consequences to the Fund.</li></ul> <ul type="square"><li style="margin-left:-20px">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.</li></ul> <ul type="square"><li style="margin-left:-20px">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.</li></ul> <ul type="square"><li style="margin-left:-20px">Subsidiary Risk — By indirectly investing in the Subsidiary through its investment in the Master Portfolio, the Fund is indirectly exposed to the risks associated with the Subsidiary’s investments. The commodity-related instruments held by the Subsidiary are generally similar to those that are permitted to be held by the Fund or the Master Portfolio and are subject to the same risks that apply to similar investments if held directly by the Fund or the Master Portfolio (see “Commodities Related Investment Risks” above). There can be no assurance that the investment objective of the Subsidiary will be achieved. The Subsidiary is not registered under the Investment Company Act, and, unless otherwise noted in this prospectus, is not subject to all the investor protections of the Investment Company Act. However, the Master Portfolio wholly owns and controls the Subsidiary, and the Master Portfolio and the Subsidiary are both managed by BlackRock, making it unlikely that the Subsidiary will take action contrary to the interests of the Fund and its shareholders. Changes in the laws of the United States and/or the Cayman Islands could result in the inability of the Fund and/or the Subsidiary to operate as described in this prospectus and the Statement of Additional Information (“SAI”) and could adversely affect the Fund.</li></ul> <ul type="square"><li style="margin-left:-20px">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.</li></ul> <div style="display:none">~ http://www.blackrock.com/role/ScheduleShareholderFeesBlackRockTotalReturnFundInvestorA1B1B2C1C2 column period compact * ~</div> <div style="display:none">~ http://www.blackrock.com/role/ScheduleAnnualFundOperatingExpensesBlackRockTotalReturnFundInvestorA1B1B2C1C2 column period compact * ~</div> <div style="display:none">~ http://www.blackrock.com/role/ScheduleExpenseExampleTransposedBlackRockTotalReturnFundInvestorA1B1B2C1C2 column period compact * ~</div> <div style="display:none">~ http://www.blackrock.com/role/ScheduleExpenseExampleNoRedemptionTransposedBlackRockTotalReturnFundInvestorA1B1B2C1C2 column period compact * ~</div> <div style="display:none">~ http://www.blackrock.com/role/ScheduleAnnualTotalReturnsBlackRockTotalReturnFundInvestorA1B1B2C1C2BarChart column period compact * ~</div> <div style="display:none">~ http://www.blackrock.com/role/ScheduleAverageAnnualTotalReturnsTransposedBlackRockTotalReturnFundInvestorA1B1B2C1C2 column period compact * ~</div> Fund Overview Key Facts about BlackRock Total Return Fund February 1, 2014 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”). 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”). 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”). 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”). A contingent deferred sales charge ("CDSC") of 0.75% is assessed on certain redemptions of Investor A Shares made within 18 months after purchase where no initial sales charge was paid at the time of purchase of an investment of $1,000,000 or more. The CDSC is 4.00% if shares are redeemed within two years. The CDSC for Investor B Shares decreases for redemptions made in subsequent years. After six years there is no CDSC on Investor B Shares. (See the section "Details about the Share Classes - Investor B Shares" for the complete schedule of CDSCs.) There is no CDSC on Investor C Shares after one year. 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"). BlackRock receives a management fee from the Master Portfolio for investment advisory and certain administrative services at the annual rate of 0.07% 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 0.38% of the Fund's average daily net assets for an overall management fee rate paid by the Fund of 0.45%. However, BlackRock has contractually agreed to waive the Fund's management fee in the amount of the Fund's share of the management fee paid by the Master Portfolio for as long as the Fund invests in the Master Portfolio. After giving effect to this waiver, BlackRock receives a fee from the Fund (including the fee paid indirectly through the Master Portfolio) at the annual rate of 0.38% of the Fund's average daily net assets. In addition, as described in the "Management of the Fund" section of the Fund's prospectus on page 41, BlackRock has contractually agreed to waive and/or reimburse fees and/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 0.90% (for Investor A Shares), 1.65% (for Investor C Shares), 0.55% (for Institutional Shares) and 1.10% (for Class R Shares) of average daily net assets until February 1, 2014. These contractual agreements may be terminated upon 90 days' notice by a majority of the independent directors of the Fund or by a vote of a majority of the outstanding voting securities of the Fund. Other expenses of the BlackRock Cayman Master Total Return Portfolio I, Ltd. (the "Subsidiary") were less than 0.01% for the Fund's last fiscal year. BlackRock receives a management fee from the Master Portfolio for investment advisory and certain administrative services at the annual rate of 0.07% 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 0.38% of the Fund's average daily net assets for an overall management fee rate paid by the Fund of 0.45%. However, BlackRock has contractually agreed to waive the Fund's management fee in the amount of the Fund's share of the management fee paid by the Master Portfolio for as long as the Fund invests in the Master Portfolio. After giving effect to this waiver, BlackRock receives a fee from the Fund (including the fee paid indirectly through the Master Portfolio) at the annual rate of 0.38% of the Fund's average daily net assets. In addition, as described in the "Management of the Fund" section of the Fund's prospectus on page 27, BlackRock has contractually agreed to waive and/or reimburse fees and/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 0.85% of average daily net assets until February 1, 2014. These contractual agreements may be terminated upon 90 days' notice by a majority of the independent directors of the Fund or by a vote of a majority of the outstanding voting securities of the Fund. BlackRock receives a management fee from the Master Portfolio for investment advisory and certain administrative services at the annual rate of 0.07% 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 0.38% of the Fund's average daily net assets for an overall management fee rate paid by the Fund of 0.45%. However, BlackRock has contractually agreed to waive the Fund's management fee in the amount of the Fund's share of the management fee paid by the Master Portfolio for as long as the Fund invests in the Master Portfolio. After giving effect to this waiver, BlackRock receives a fee from the Fund (including the fee paid indirectly through the Master Portfolio) at the annual rate of 0.38% of the Fund's average daily net assets. In addition, as described in the "Management of the Fund" section of the Fund's prospectus on page 26, BlackRock has contractually agreed to waive and/or reimburse fees and/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 0.40% of average daily net assets until February 1, 2014. These contractual agreements may be terminated upon 90 days' notice by a majority of the independent directors of the Fund or by a vote of a majority of the outstanding voting securities of the Fund. BlackRock receives a management fee from the Master Portfolio for investment advisory and certain administrative services at the annual rate of 0.07% 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 0.38% of the Fund's average daily net assets for an overall management fee rate paid by the Fund of 0.45%. However, BlackRock has contractually agreed to waive the Fund's management fee in the amount of the Fund's share of the management fee paid by the Master Portfolio for as long as the Fund invests in the Master Portfolio. After giving effect to this waiver, BlackRock receives a fee from the Fund (including the fee paid indirectly through the Master Portfolio) at the annual rate of 0.38% of the Fund's average daily net assets. 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 and/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 1.65% (for Investor B2 Shares) of average daily net assets until February 1, 2014. These contractual agreements may be terminated upon 90 days' notice by a majority of the independent directors of the Fund or by a vote of a majority of the outstanding voting securities of the Fund. Other expenses of the BlackRock Cayman Master Total Return Portfolio I, Ltd. (the "Subsidiary") were less than 0.01% for the Fund's last fiscal year. For the year ended September 30, 2012, the Investor B2 Shares did not pay distribution fees due to regulatory fee limits. The Total Annual Fund Operating Expenses have been restated to reflect as if the distribution fees had been paid. A contingent deferred sales charge ("CDSC") of 1.00% is assessed if shares are redeemed within one year. The CDSC for Investor B1 Shares decreases for redemptions made in subsequent years. After three years there is no CDSC on Investor B1 Shares. The CDSC is 4.50% if shares are redeemed within one year. The CDSC for Investor B2 Shares decreases for redemptions made in subsequent years. After six years there is no CDSC on Investor B2 Shares. There is no CDSC on Investor C1 and Investor C2 Shares after one year.