MFS Corporate Bond Fund
MFS Series Trust IX · 9 share classes
Fund classification
Classified from what the fund holds · as of 2026 Q2
MFS Corporate Bond Fund is an actively managed U.S. bond fund.
- Asset class
- Bonds
- Region
- United States
- Management
- Actively managed
- Fund type
- Open-end fund
- Credit quality
- Investment grade
- Rate sensitivity
- Intermediate duration
Fund profile
As filed in the prospectus · 2025 Q3
The funds investment objective is to seek total return with an emphasis on current income, but also considering capital appreciation.
The fund invests at least 80% of assets in corporate debt instruments selected through bottom-up fundamental analysis, with the majority in investment-grade quality but up to a significant portion in below-investment-grade debt; it may also hold U.S. Government securities and foreign securities across sectors. Because the fund may invest meaningfully in below-investment-grade debt instruments, credit risk is material to returns.
| Share class | Gross | Net |
|---|---|---|
| MFBFX | 0.77% | 0.76% |
| MFBJX | 0.52% | 0.51% |
| MFBBX | 1.52% | 1.51% |
| MFBCX | 1.52% | 1.51% |
| MBDIX | 0.52% | 0.51% |
| MFBGX | 1.52% | 1.51% |
| MBRRX | 1.02% | 1.01% |
| MFBHX | 0.77% | 0.76% |
| MFBKX | 0.43% | 0.42% |
Net is what a holder pays after the adviser's contractual waiver; gross is before it. A waiver can expire.
Portfolio turnover 38.00% · as of 2025 Q3
Allocation
Asset groups · long / short shown separately, never netted · 2026 Q2
| Bonds | 94.47% |
| Securitized | 3.19% |
| Cash & short-term | 1.76% |
| Derivatives | -0.17% |
The outer band is exposure held short — written against the portfolio rather than part of it, which is why it sits outside the ring and why the two are never netted into one figure.
Derivatives are shown at market value, not notional exposure.
Sector allocation
The same holdings as Allocation above, grouped by market sector instead of asset type · as of 2026 Q2
| Other | 22.1% |
| International | 21.9% |
| Financials | 16.0% |
| Utilities | 6.0% |
| 12 smaller | 33.9% |
Government, Securitized and Cash are non-corporate buckets; International is foreign holdings we don’t sector-classify, and Other is the residual (held funds, unresolved names).
Latest quarter
What changed since the fund's previous filing
Largest new: Spire, Inc., Amazon.com, Inc., Citadel Securities Global Holdings LLC, United States of America, Cheniere Energy Partners LP, WSP Global, Inc., Oracle Corp., Abbott Laboratories
Largest exited: Royal Caribbean Cruises Ltd., Cheniere Energy Partners LP, Adani Transmission Step-One Ltd., Kingdom of Saudi Arabia, Marathon Petroleum Corp., DTE Energy Co., Boston Properties LP, Amazon.com, Inc.
Return profile
Total return as filed — price change plus distributions reinvested · trailing figures to Apr 2026
| Share class | 1-year | 3-year | 5-year | Vol | Worst fall |
|---|---|---|---|---|---|
| +5.21% | +14.65% | +2.26% | 3.38% | -5.91% | |
| +5.64% | +15.70% | +3.79% | 3.37% | -5.78% | |
| +4.43% | +12.13% | -1.48% | 3.43% | -6.28% | |
| +4.41% | +12.14% | -1.49% | 3.39% | -6.20% | |
| +5.54% | +15.52% | +3.62% | 3.40% | -5.79% | |
| +4.52% | +12.12% | -1.40% | 3.41% | -6.27% | |
| +4.95% | +13.81% | +1.07% | 3.44% | -6.03% | |
| +5.22% | +14.65% | +2.35% | 3.46% | -5.90% | |
| +5.65% | +15.83% | +4.09% | 3.38% | -5.76% |
These classes hold the same portfolio, so the 5.58pp spread over 5 years is the cost difference between them — roughly 1.12pp a year — not a difference in what they own.
Debt profile
What this fund holds — value-weighted across its bond and securitized long positions · as of 2026-04-30
Share of the fund's debt by how its coupon behaves — the fact that decides whether a rate move reaches this portfolio at all.
| Fixed rate | 78.9% |
| Floating rate | 21.1% |
Share of the fund's debt value in each maturity band, shortest first.
| <1y | 1.6% |
| 1-3y | 11.2% |
| 3-5y | 17.8% |
| 5-10y | 40.1% |
| 10y+ | 29.3% |
These three overlap — one holding can be in arrears and paying in kind at once — so they are shown separately and never summed.
Risk profile
Interest-rate and credit-spread sensitivity, both in years · as of 2026Q2
Most of this fund’s sensitivity is to interest rates, with credit spreads carrying nearly as much.
Where the loss would come from. The two shocks are the same size, so this is the balance of the fund's two sensitivities rather than a bet on one moving more.
| Interest rates | 52% |
| Credit spreads | 48% |
Filers report the impact of a 0.01% move only, so the total is our own scaling of that one number and overstates the loss on most bonds — read it as approximate, never as precise. The two sensitivities overlap rather than add up: they measure the same positions against different shocks, which is why the durations above are shown side by side and never summed.
Share of the fund's spread duration carried by each credit tier.
| Investment grade | +5.70 yr |
| High yield | +0.37 yr |
Share of duration at each point, shortest first. A positive figure loses value when spreads widen; a negative one offsets — a credit hedge.
| 3 mo | 0.02 yr | 0% |
| 1 yr | 0.53 yr | 8% |
| 5 yr | 1.95 yr | 29% |
| 10 yr | 2.67 yr | 40% |
| 30 yr | 1.52 yr | 23% |
| 3 mo | 0.02 yr | 0% |
| 1 yr | 0.49 yr | 8% |
| 5 yr | 1.91 yr | 31% |
| 10 yr | 2.46 yr | 41% |
| 30 yr | 1.18 yr | 19% |
The two bands measure the same positions against different shocks and do not add — a Treasury carries rate duration and no spread duration, a floating-rate credit the reverse. Rate tenors are also summed across every currency the fund discloses.
Show the numbers
| Tenor | Rate yrs | IG yrs | HY yrs | IG $/bp | HY $/bp |
|---|---|---|---|---|---|
| 3 mo | +0.02 | +0.02 | +0.00 | $8.1k | $1.4k |
| 1 yr | +0.53 | +0.41 | +0.08 | $178.8k | $37.0k |
| 5 yr | +1.95 | +1.73 | +0.17 | $760.4k | $76.3k |
| 10 yr | +2.67 | +2.38 | +0.08 | $1.04m | $34.8k |
| 30 yr | +1.52 | +1.15 | +0.03 | $505.6k | $11.7k |
Dollar change per 1bp of spread movement, as filed and sign-anchored. A blank cell was not filed; a zero was.
Duration contribution in years, summing to the fund's 6.68 yr.
This is where the fund's rate exposure sits, not its currency risk — most international bond funds hedge the currency back to dollars, and the size of those hedges is not in the filing. Tenors are also summed across curves, so a 5-year JPY point and a 5-year USD point are added together.
Holdings
By % of NAV · equity positions carry filed share counts · every resolvable issuer links to its company page
| Ticker | Issuer | %NAV | Value | Shares |
|---|---|---|---|---|
| — | MFS Institutional Money Market Portfolio | 1.76% | $77.33M | — |
| — | UBS Group AG3.13% floating · due 2030-08-13 | 0.77% | $33.88M | — |
| — | JPMorgan Chase & Co.2.54% floating · due 2032-11-08 | 0.76% | $33.15M | — |
| — | Boeing Co. (The)5.80% · due 2050-05-01 | 0.74% | $32.61M | — |
| — | Charles Schwab Corp. (The)4.91% floating · due 2036-11-14 | 0.62% | $27.03M | — |
| — | Bermuda5.00% · due 2032-07-15 | 0.59% | $25.69M | — |
| — | Morgan Stanley5.07% floating · due 2037-01-30 | 0.58% | $25.28M | — |
| — | Sumitomo Mitsui Financial Group, Inc.1.71% · due 2031-01-12 | 0.57% | $25.14M | — |
| — | UBS Group AG5.58% floating · due 2036-05-09 | 0.54% | $23.70M | — |
| — | CaixaBank SA6.84% floating · due 2034-09-13 | 0.54% | $23.47M | — |
Top 10 positions are 7.47% of net assets, top 25 14.37%, across 261 issuers.
See more of this fund's book
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