MCBFX Holdings — MFS Core Bond Fund
Data updated: 2026-09-28
MCBFX holds 318 securities. The top 10 make up 20.2% of net assets, led by U.S. Treasury Notes (4.19%) and MFS Institutional Money Market Portfolio, Class A (3.28%). Mortgage / Securitized (45.2%) and Corporate Bonds (31.9%) are the largest sectors, and 82.7% of the portfolio is in United States. Debt holdings: 126 positions, 50.7% of assets.
Holdings cover 102.17% of net asset value (98.22% of total assets; remainder is cash and receivables). As of July 31, 2026 · N-PORT.
MCBFX Portfolio Holdings
318 holdings of MFS Core 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 318.
| Holding | Ticker | Sector | % of net assets | Value (USD) |
|---|---|---|---|---|
| U.S. Treasury Notes | — | Government Bonds | 4.19% | $1.44M |
| MFS Institutional Money Market Portfolio, Class A | — | Funds & ETFs | 3.28% | $1.13M |
| U.S. Treasury Bonds | — | Government Bonds | 2.60% | $896.62K |
| U.S. Treasury Bonds | — | Government Bonds | 2.57% | $885.19K |
| U.S. Treasury Bonds | — | Government Bonds | 1.49% | $513.42K |
| U.S. Treasury Bonds | — | Government Bonds | 1.28% | $441.51K |
| U.S. Treasury Notes | — | Government Bonds | 1.28% | $441.49K |
| Umbs | — | Mortgage / Securitized | 1.19% | $408.28K |
| UMBS, 30 Year, Single Family | — | Mortgage / Securitized | 1.17% | $404.40K |
| NTT Finance Corp. | — | Corporate Bonds | 1.15% | $396.26K |
| U.S. Treasury Bonds | — | Government Bonds | 1.14% | $391.80K |
| Umbs | — | Mortgage / Securitized | 1.08% | $371.62K |
| U.S. Treasury Bonds | — | Government Bonds | 1.06% | $363.19K |
| U.S. Treasury Bonds | — | Government Bonds | 0.91% | $311.97K |
| U.S. Treasury Notes | — | Government Bonds | 0.87% | $299.13K |
| UMBS, 30 Year, Single Family | — | Mortgage / Securitized | 0.79% | $272.56K |
| Umbs | — | Mortgage / Securitized | 0.78% | $268.63K |
| Bank of America Corp. | — | Corporate Bonds | 0.77% | $266.24K |
| Dryden 86 CLO Ltd., Series 2020-86A, Class BR2 | — | Mortgage / Securitized | 0.73% | $250.33K |
| Dryden 68 CLO Ltd., Series 2019-68A, Class BRR | — | Mortgage / Securitized | 0.73% | $250.17K |
| Bain Capital Credit CLO Ltd., Series 2022-1A, Class CR | — | Mortgage / Securitized | 0.73% | $250.15K |
| Shackleton 2019-XIV CLO Ltd., Series 2019-14A, Class CRR | — | Mortgage / Securitized | 0.73% | $250.01K |
| Dryden 113 CLO Ltd., Series 2022-113A, Class AR3 | — | Mortgage / Securitized | 0.73% | $250.03K |
| Oaktree CLO Ltd., Series 2019-4A, Class BR3 | — | Mortgage / Securitized | 0.73% | $249.98K |
| MF1 Ltd., Series 2021-FL7, Class AS | — | Mortgage / Securitized | 0.73% | $249.87K |
| Palmer Square Loan Funding Ltd., Series 2024-3A, Class A2R | — | Mortgage / Securitized | 0.73% | $249.74K |
| Umbs | — | Mortgage / Securitized | 0.66% | $227.92K |
| Boston Properties LP | — | Corporate Bonds | 0.65% | $225.33K |
| Eni SpA | — | Corporate Bonds | 0.60% | $207.63K |
| Anglo American Capital plc | — | Corporate Bonds | 0.59% | $203.49K |
| Ashtead Capital, Inc. | — | Corporate Bonds | 0.58% | $201.24K |
| Mitsubishi UFJ Financial Group, Inc. | — | Corporate Bonds | 0.58% | $200.88K |
| Umbs | — | Mortgage / Securitized | 0.58% | $200.07K |
| Bain Capital Credit CLO Ltd., Series 2020-3A, Class BR3 | — | Mortgage / Securitized | 0.58% | $200.02K |
| SMBC Aviation Capital Finance DAC | — | Corporate Bonds | 0.57% | $197.86K |
| Bayer US Finance LLC | — | Corporate Bonds | 0.57% | $196.41K |
| U.S. Treasury Notes | — | Government Bonds | 0.56% | $194.22K |
| U.S. Treasury Bonds | — | Government Bonds | 0.55% | $190.59K |
| Diageo Capital plc | — | Corporate Bonds | 0.54% | $185.91K |
| Alcon Finance Corp. | — | Corporate Bonds | 0.53% | $183.94K |
| TRTX Issuer Ltd., Series 2025-FL7, Class A | — | Mortgage / Securitized | 0.53% | $183.08K |
| Umbs | — | Mortgage / Securitized | 0.53% | $182.64K |
| BDS LLC, Series 2026-FL17, Class A | — | Mortgage / Securitized | 0.53% | $181.78K |
| Waste Management, Inc. | — | Corporate Bonds | 0.51% | $176.85K |
| MSWF Commercial Mortgage Trust, Series 2023-2, Class A5 | — | Mortgage / Securitized | 0.51% | $176.16K |
| UBS Group AG | — | Corporate Bonds | 0.51% | $174.95K |
| Wells Fargo Commercial Mortgage Trust, Series 2017-RB1, Class A5 | — | Mortgage / Securitized | 0.50% | $172.70K |
| ACRES Commercial Realty Issuer LLC, Series 2026-FL4, Class A | — | Mortgage / Securitized | 0.50% | $171.11K |
| MF1 LLC, Series 2026-FL22, Class AS | — | Mortgage / Securitized | 0.50% | $170.92K |
| LPL Holdings, Inc. | — | Corporate Bonds | 0.49% | $169.38K |
| Stellantis Finance US, Inc. | — | Corporate Bonds | 0.49% | $168.90K |
| Umbs | — | Mortgage / Securitized | 0.49% | $168.12K |
| Enbridge, Inc. | — | Corporate Bonds | 0.49% | $167.97K |
| Plains All American Pipeline LP | — | Corporate Bonds | 0.48% | $166.05K |
| MF1 LLC, Series 2025-FL20, Class AS | — | Mortgage / Securitized | 0.48% | $164.51K |
| Umbs | — | Mortgage / Securitized | 0.47% | $160.87K |
| Goldman Sachs Group, Inc. (The) | — | Corporate Bonds | 0.46% | $158.85K |
| Umbs | — | Mortgage / Securitized | 0.46% | $158.86K |
| Charles Schwab Corp. (The) | — | Corporate Bonds | 0.46% | $158.45K |
| ARDN Mortgage Trust, Series 2025-ARCP, Class A | — | Mortgage / Securitized | 0.46% | $158.15K |
| BAT International Finance plc | — | Corporate Bonds | 0.46% | $157.51K |
| East Ohio Gas Co. (The) | — | Corporate Bonds | 0.46% | $157.34K |
| MF1, Series 2024-FL16, Class A | — | Mortgage / Securitized | 0.45% | $155.03K |
| Japan Tobacco, Inc. | — | Corporate Bonds | 0.45% | $154.64K |
| Umbs | — | Mortgage / Securitized | 0.45% | $154.02K |
| Deutsche Bank AG | — | Corporate Bonds | 0.45% | $153.96K |
| Capital One Financial Corp. | — | Corporate Bonds | 0.45% | $153.43K |
| DCP Midstream Operating LP | — | Corporate Bonds | 0.44% | $151.91K |
| Anheuser-Busch InBev Worldwide, Inc. | — | Corporate Bonds | 0.44% | $149.89K |
| Venture 43 CLO Ltd., Series 2021-43A, Class BRR | — | Mortgage / Securitized | 0.43% | $149.58K |
| AerCap Ireland Capital DAC | — | Corporate Bonds | 0.43% | $149.33K |
| Anheuser-Busch InBev Worldwide, Inc. | — | Corporate Bonds | 0.43% | $149.08K |
| Deutsche Bank AG | — | Corporate Bonds | 0.43% | $148.98K |
| BANK, Series 2023-BNK46, Class A4 | — | Mortgage / Securitized | 0.43% | $148.89K |
| PNC Financial Services Group, Inc. (The) | — | Corporate Bonds | 0.43% | $148.51K |
| Wells Fargo & Co. | — | Corporate Bonds | 0.43% | $147.35K |
| Metropolitan Life Global Funding I | — | Corporate Bonds | 0.42% | $144.63K |
| Targa Resources Corp. | — | Corporate Bonds | 0.42% | $143.32K |
| Macquarie Group Ltd. | — | Corporate Bonds | 0.41% | $141.32K |
| Aspire Mortgage Trust, Series 2026-3, Class A1 | — | Mortgage / Securitized | 0.40% | $138.99K |
| U.S. Treasury Bonds | — | Government Bonds | 0.40% | $138.51K |
| BDS LLC, Series 2025-FL16, Class A | — | Mortgage / Securitized | 0.40% | $136.94K |
| Gnma | — | Mortgage / Securitized | 0.39% | $135.67K |
| Umbs | — | Mortgage / Securitized | 0.39% | $135.64K |
| U.S. Treasury Bonds | — | Government Bonds | 0.39% | $135.60K |
| Rogers Communications, Inc. | — | Corporate Bonds | 0.39% | $134.38K |
| Energy Transfer LP | — | Corporate Bonds | 0.39% | $132.88K |
| BDS LLC, Series 2026-FL18, Class AS | — | Mortgage / Securitized | 0.38% | $132.03K |
| Arrow Electronics, Inc. | — | Corporate Bonds | 0.38% | $129.10K |
| Gnma | — | Mortgage / Securitized | 0.36% | $123.18K |
| Gnma | — | Mortgage / Securitized | 0.35% | $120.85K |
| Gnma | — | Mortgage / Securitized | 0.34% | $118.14K |
| Duke Energy Carolinas LLC | — | Corporate Bonds | 0.34% | $116.97K |
| Broadcom, Inc. | — | Corporate Bonds | 0.34% | $115.76K |
| PFP Ltd., Series 2025-12, Class AS | — | Mortgage / Securitized | 0.34% | $115.78K |
| Duke Energy Progress LLC | — | Corporate Bonds | 0.33% | $114.52K |
| Humana, Inc. | — | Corporate Bonds | 0.33% | $113.89K |
| Morgan Stanley | — | Corporate Bonds | 0.33% | $112.94K |
| PMT Loan Trust, Series 2026-INV2, Class A35 | — | Mortgage / Securitized | 0.33% | $112.68K |
| Umbs | — | Mortgage / Securitized | 0.32% | $110.92K |
MCBFX Sector Allocation
MFS Core Bond Fund holdings grouped by sector, by share of the portfolio's market value.
| Sector | Weight | Holdings |
|---|---|---|
| Mortgage / Securitized | 45.2% | 188 |
| Corporate Bonds | 31.9% | 108 |
| Government Bonds | 19.4% | 16 |
| Funds & ETFs | 3.2% | 1 |
| Municipal Bonds | 0.4% | 2 |
| Unknown | -0.1% | 3 |
MCBFX Country Allocation
Where MFS Core Bond Fund's holdings are domiciled, by percentage of net assets (largest 11).
| Country | % of net assets |
|---|---|
| United States | 82.7% |
| Cayman Islands | 8.7% |
| Japan | 2.2% |
| Canada | 2.0% |
| United Kingdom | 1.9% |
| Ireland | 1.3% |
| Germany | 0.9% |
| Jersey | 0.7% |
| Australia | 0.7% |
| Italy | 0.6% |
| Switzerland | 0.5% |
MCBFX Portfolio Allocation
Asset-class allocation of MFS Core Bond Fund by percentage of net assets, from the latest SEC N-PORT filing.
| Asset class | Allocation |
|---|---|
| Fixed Income | 52.8% |
| Securitized | 46.2% |
| Cash & Equivalents | 3.3% |
MCBFX Debt Constituents
Largest debt holdings of MFS Core Bond Fund by percentage of net assets, from the latest SEC N-PORT filing.
| Debt holding | % of net assets |
|---|---|
| United States of America | 4.19% |
| United States of America | 2.60% |
| United States of America | 2.57% |
| United States of America | 1.49% |
| United States of America | 1.28% |
| United States of America | 1.28% |
| NTT Finance Corp. | 1.15% |
| United States of America | 1.14% |
| United States of America | 1.06% |
| United States of America | 0.91% |
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.