MRBCX Holdings — MFS Total Return Bond Fund
Data updated: 2026-09-28
MRBCX holds 1,082 securities. The top 10 make up 14.9% of net assets, led by MFS Institutional Money Market Portfolio, Class A (2.17%) and U.S. Treasury Bonds (2.08%). Mortgage / Securitized (38.9%) and Corporate Bonds (37.4%) are the largest sectors, and 83.2% of the portfolio is in United States. Debt holdings: 233 positions, 58.5% of assets.
Holdings cover 100.52% of net asset value (99.09% of total assets; remainder is cash and receivables). As of July 31, 2026 · N-PORT.
MRBCX Portfolio Holdings
1,082 holdings of MFS Total Return Bond Fund by percentage of net assets, from the fund's SEC N-PORT filing as of July 31, 2026. The 100 largest are listed below; the interactive table on this page lists all 1,082.
| Holding | Ticker | Sector | % of net assets | Value (USD) |
|---|---|---|---|---|
| MFS Institutional Money Market Portfolio, Class A | — | Funds & ETFs | 2.17% | $175.66M |
| U.S. Treasury Bonds | — | Government Bonds | 2.08% | $168.27M |
| U.S. Treasury Notes | — | Government Bonds | 2.06% | $166.59M |
| U.S. Treasury Bonds | — | Government Bonds | 1.92% | $155.63M |
| U.S. Treasury Notes | — | Government Bonds | 1.23% | $99.71M |
| U.S. Treasury Bonds | — | Government Bonds | 1.14% | $92.03M |
| U.S. Treasury Notes | — | Government Bonds | 1.14% | $92.02M |
| U.S. Treasury Bonds | — | Government Bonds | 1.10% | $88.63M |
| Umbs | — | Mortgage / Securitized | 1.05% | $85.31M |
| U.S. Treasury Bonds | — | Government Bonds | 1.03% | $82.98M |
| U.S. Treasury Notes | — | Government Bonds | 0.87% | $70.26M |
| U.S. Treasury Bonds | — | Government Bonds | 0.81% | $65.70M |
| U.S. Treasury Notes | — | Government Bonds | 0.79% | $64.01M |
| U.S. Treasury Notes | — | Government Bonds | 0.78% | $63.13M |
| U.S. Treasury Bonds | — | Government Bonds | 0.76% | $61.47M |
| UMBS, 30 Year, Single Family | — | Mortgage / Securitized | 0.76% | $61.39M |
| U.S. Treasury Notes | — | Government Bonds | 0.68% | $55.35M |
| U.S. Treasury Bonds | — | Government Bonds | 0.57% | $46.12M |
| Macquarie Group Ltd. | — | Corporate Bonds | 0.56% | $45.09M |
| Cheniere Energy Partners LP | — | Corporate Bonds | 0.54% | $43.85M |
| U.S. Treasury Bonds | — | Government Bonds | 0.54% | $43.49M |
| U.S. Treasury Bonds | — | Government Bonds | 0.54% | $43.30M |
| U.S. Treasury Bonds | — | Government Bonds | 0.53% | $43.24M |
| Wells Fargo & Co. | — | Corporate Bonds | 0.52% | $41.86M |
| Bank of America Corp. | — | Corporate Bonds | 0.50% | $40.45M |
| Arbor Realty Commercial Real Estate Notes Ltd., Series 2022-FL1, Class D | — | Mortgage / Securitized | 0.50% | $40.35M |
| LoanCore Issuer LLC, Series 2025-CRE8, Class AS | — | Mortgage / Securitized | 0.49% | $39.81M |
| U.S. Treasury Notes | — | Government Bonds | 0.47% | $38.29M |
| BXMT Ltd., Series 2021-FL4, Class B | — | Mortgage / Securitized | 0.47% | $38.23M |
| Capital One Financial Corp. | — | Corporate Bonds | 0.45% | $36.67M |
| Bank of America Corp. | — | Corporate Bonds | 0.45% | $36.65M |
| MF1 LLC, Series 2026-FL22, Class B | — | Mortgage / Securitized | 0.42% | $34.19M |
| Sumitomo Mitsui Financial Group, Inc. | — | Corporate Bonds | 0.42% | $34.06M |
| Black Diamond CLO Ltd., Series 2021-1A, Class A2R | — | Mortgage / Securitized | 0.42% | $34.05M |
| Iron Mountain, Inc. | — | Corporate Bonds | 0.42% | $34.02M |
| LoanCore Issuer Ltd., Series 2021-CRE6, Class B | — | Mortgage / Securitized | 0.41% | $33.37M |
| Aspire Mortgage Trust, Series 2026-3, Class A1 | — | Mortgage / Securitized | 0.41% | $33.01M |
| Penske Automotive Group, Inc. | — | Corporate Bonds | 0.41% | $33.00M |
| TransDigm, Inc. | — | Corporate Bonds | 0.40% | $32.48M |
| UBS Commercial Mortgage Trust, Series 2017-C7, Class A4 | — | Mortgage / Securitized | 0.40% | $32.45M |
| Plains All American Pipeline LP | — | Corporate Bonds | 0.39% | $31.85M |
| New Residential Mortgage Loan Trust, Series 2025-NQM4, Class A1 | — | Mortgage / Securitized | 0.39% | $31.70M |
| Elmwood CLO VIII Ltd., Series 2021-1A, Class CRR | — | Mortgage / Securitized | 0.39% | $31.43M |
| ENEL Finance International NV | — | Corporate Bonds | 0.37% | $29.69M |
| Angel Oak Mortgage Trust, Series 2026-3, Class A1 | — | Mortgage / Securitized | 0.36% | $29.22M |
| Quikrete Holdings, Inc. | — | Corporate Bonds | 0.36% | $29.08M |
| Paychex, Inc. | — | Corporate Bonds | 0.36% | $28.99M |
| Venture 43 CLO Ltd., Series 2021-43A, Class BRR | — | Mortgage / Securitized | 0.35% | $28.63M |
| QXO Building Products, Inc. | — | Corporate Bonds | 0.35% | $28.53M |
| ARDN Mortgage Trust, Series 2025-ARCP, Class B | — | Mortgage / Securitized | 0.35% | $28.41M |
| U.S. Treasury Bonds | — | Government Bonds | 0.35% | $28.38M |
| Sammons Financial Group, Inc. | — | Corporate Bonds | 0.35% | $28.15M |
| Mitsubishi UFJ Financial Group, Inc. | — | Corporate Bonds | 0.35% | $27.93M |
| JPMorgan Chase & Co. | — | Corporate Bonds | 0.34% | $27.78M |
| UBS Group AG | — | Corporate Bonds | 0.34% | $27.29M |
| Eni SpA | — | Corporate Bonds | 0.33% | $27.09M |
| Energy Transfer LP | — | Corporate Bonds | 0.33% | $26.93M |
| Charles Schwab Corp. (The), Series K | — | Corporate Bonds | 0.33% | $26.75M |
| Commercial Mortgage Trust, Series 2017-COR2, Class A3 | — | Mortgage / Securitized | 0.33% | $26.46M |
| BAT Capital Corp. | — | Corporate Bonds | 0.32% | $26.05M |
| Boston Properties LP | — | Corporate Bonds | 0.32% | $25.79M |
| Regal Rexnord Corp. | — | Corporate Bonds | 0.32% | $25.77M |
| T-Mobile USA, Inc. | — | Corporate Bonds | 0.32% | $25.76M |
| Beach Acquisition Bidco LLC | — | Corporate Bonds | 0.32% | $25.64M |
| JPMorgan Chase & Co. | — | Corporate Bonds | 0.32% | $25.55M |
| U.S. Treasury Bonds | — | Government Bonds | 0.31% | $25.39M |
| Brixmor Operating Partnership LP | — | Corporate Bonds | 0.31% | $25.32M |
| Deutsche Bank AG | — | Corporate Bonds | 0.31% | $25.28M |
| Targa Resources Corp. | — | Corporate Bonds | 0.31% | $25.12M |
| Pacific Gas and Electric Co. | — | Corporate Bonds | 0.31% | $24.99M |
| Wells Fargo Commercial Mortgage Trust, Series 2016-LC25, Class A4 | — | Mortgage / Securitized | 0.31% | $24.96M |
| Dell International LLC | — | Corporate Bonds | 0.31% | $24.95M |
| Gnma | — | Mortgage / Securitized | 0.31% | $24.88M |
| Genmab A/s | — | Corporate Bonds | 0.30% | $24.62M |
| Venture Global Calcasieu Pass LLC | — | Corporate Bonds | 0.30% | $24.55M |
| Gnma | — | Mortgage / Securitized | 0.30% | $24.49M |
| OAK-Eagle Acquireco, Inc. | — | Corporate Bonds | 0.30% | $24.48M |
| New Residential Mortgage Loan Trust, Series 2026-NQM9, Class A1 | — | Mortgage / Securitized | 0.30% | $24.47M |
| NTT Finance Corp. | — | Corporate Bonds | 0.30% | $24.36M |
| SS&C Technologies, Inc. | — | Corporate Bonds | 0.30% | $24.34M |
| Ashtead Capital, Inc. | — | Corporate Bonds | 0.30% | $24.29M |
| Gnma | — | Mortgage / Securitized | 0.30% | $24.06M |
| Toledo Hospital (The), Series B | — | Corporate Bonds | 0.30% | $23.99M |
| Black Diamond CLO Ltd., Series 2019-2A, Class A2R | — | Mortgage / Securitized | 0.30% | $23.91M |
| BAT International Finance plc | — | Corporate Bonds | 0.29% | $23.86M |
| Vodafone Group plc | — | Corporate Bonds | 0.29% | $23.82M |
| Acrec 2025 Fl LLC, Series 2025-FL3, Class AS | — | Mortgage / Securitized | 0.29% | $23.76M |
| Goldman Sachs Group, Inc. (The) | — | Corporate Bonds | 0.29% | $23.66M |
| HSBC Holdings plc | — | Corporate Bonds | 0.29% | $23.60M |
| Charles Schwab Corp. (The) | — | Corporate Bonds | 0.29% | $23.53M |
| Macquarie Bank Ltd. | — | Corporate Bonds | 0.29% | $23.44M |
| MF1 LLC, Series 2025-FL20, Class B | — | Mortgage / Securitized | 0.29% | $23.40M |
| HUB International Ltd. | — | Corporate Bonds | 0.29% | $23.32M |
| MF1, Series 2024-FL16, Class AS | — | Mortgage / Securitized | 0.28% | $23.05M |
| Deutsche Bank AG | — | Corporate Bonds | 0.28% | $23.02M |
| U.S. Treasury Bonds | — | Government Bonds | 0.28% | $22.90M |
| BANK, Series 2023-BNK46, Class A4 | — | Mortgage / Securitized | 0.28% | $22.48M |
| Village of Bridgeview | — | Municipal Bonds | 0.28% | $22.45M |
| Brsp 2026-Fl3 Ltd., Series 2026-FL3, Class AS | — | Mortgage / Securitized | 0.28% | $22.42M |
| Boeing Co. (The) | — | Corporate Bonds | 0.28% | $22.27M |
MRBCX Sector Allocation
MFS Total Return Bond Fund holdings grouped by sector, by share of the portfolio's market value.
| Sector | Weight | Holdings |
|---|---|---|
| Mortgage / Securitized | 38.9% | 844 |
| Corporate Bonds | 37.4% | 200 |
| Government Bonds | 20.7% | 26 |
| Funds & ETFs | 2.2% | 1 |
| Municipal Bonds | 0.9% | 7 |
| Unknown | -0.1% | 4 |
MRBCX Country Allocation
Where MFS Total Return Bond Fund's holdings are domiciled, by percentage of net assets (largest 14).
| Country | % of net assets |
|---|---|
| United States | 83.2% |
| Cayman Islands | 8.4% |
| United Kingdom | 1.9% |
| Canada | 1.5% |
| Australia | 1.4% |
| Japan | 1.1% |
| Germany | 0.6% |
| Italy | 0.5% |
| Ireland | 0.5% |
| Switzerland | 0.5% |
| Netherlands | 0.4% |
| Denmark | 0.3% |
| Jersey | 0.2% |
| France | 0.1% |
MRBCX Portfolio Allocation
Asset-class allocation of MFS Total Return Bond Fund by percentage of net assets, from the latest SEC N-PORT filing.
| Asset class | Allocation |
|---|---|
| Fixed Income | 59.4% |
| Securitized | 39.1% |
| Cash & Equivalents | 2.2% |
MRBCX Debt Constituents
Largest debt holdings of MFS Total Return Bond Fund by percentage of net assets, from the latest SEC N-PORT filing.
| Debt holding | % of net assets |
|---|---|
| United States of America | 2.08% |
| United States of America | 2.06% |
| United States of America | 1.92% |
| United States of America | 1.23% |
| United States of America | 1.14% |
| United States of America | 1.14% |
| United States of America | 1.10% |
| United States of America | 1.03% |
| United States of America | 0.87% |
| United States of America | 0.81% |
For information only. Not investment advice: figures are as reported in SEC filings and may contain errors or be out of date. Past performance does not guarantee future results.