MFS Total Return Bond Fund
MFS Series Trust IX · 9 share classes
Fund classification
Classified from what the fund holds · as of 2026 Q2
MFS Total Return 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 debt instruments selected through bottom-up fundamental analysis, including investment-grade and below-investment-grade corporate bonds, government securities, mortgage-backed securities, and other fixed-income instruments across sectors and geographies. The manager may concentrate a significant portion of assets in a single issuer or sector. Because the fund may invest meaningfully in below-investment-grade debt and concentrate holdings, credit risk and issuer-specific risk are material to returns.
| Share class | Gross | Net |
|---|---|---|
| MRBFX | 0.77% | 0.60% |
| MRBJX | 0.52% | 0.45% |
| MRBBX | 1.52% | 1.35% |
| MRBCX | 1.52% | 1.45% |
| MRBIX | 0.52% | 0.45% |
| MRBGX | 1.52% | 1.45% |
| MRRRX | 1.02% | 0.95% |
| MRBHX | 0.77% | 0.70% |
| MRBKX | 0.42% | 0.36% |
Net is what a holder pays after the adviser's contractual waiver; gross is before it. A waiver can expire.
Portfolio turnover 75.00% · as of 2025 Q3
Allocation
Asset groups · long / short shown separately, never netted · 2026 Q2
| Bonds | 61.71% |
| Securitized | 37.33% |
| Cash & short-term | 1.53% |
| Derivatives | -0.25% |
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
| Securitized | 37.1% |
| Government | 25.2% |
| Other | 10.0% |
| Financials | 8.2% |
| 12 smaller | 19.6% |
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: Cheniere Energy Partners LP, FNMA or FHLMC, Venture 43 CLO Ltd., Beach Acquisition Bidco LLC, GNMA, Asurion LLC, Brsp 2026-Fl3 Ltd., Jefferies Financial Group, Inc.
Largest exited: FNMA or FHLMC ×2, Cheniere Energy Partners LP, Venture 43 CLO Ltd., Boeing Co. (The), FNMA, LoanCore Issuer Ltd., GNMA
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 |
|---|---|---|---|---|---|
| +4.39% | +12.98% | +2.46% | 3.34% | -5.50% | |
| +4.57% | +13.50% | +3.23% | 3.35% | -5.42% | |
| +3.62% | +10.46% | -1.31% | 3.35% | -5.84% | |
| +3.53% | +10.17% | -1.78% | 3.35% | -5.89% | |
| +4.58% | +13.49% | +3.23% | 3.34% | -5.43% | |
| +3.53% | +10.26% | -1.71% | 3.38% | -5.89% | |
| +4.05% | +11.82% | +0.67% | 3.35% | -5.67% | |
| +4.30% | +12.63% | +1.92% | 3.35% | -5.56% | |
| +4.64% | +13.80% | +3.71% | 3.41% | -5.38% |
These classes hold the same portfolio, so the 5.50pp spread over 5 years is the cost difference between them — roughly 1.10pp 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 | 73.4% |
| Floating rate | 26.3% |
| Zero-coupon or unclassified | 0.2% |
Share of the fund's debt value in each maturity band, shortest first.
| <1y | 4.4% |
| 1-3y | 10.3% |
| 3-5y | 14.3% |
| 5-10y | 23.4% |
| 10y+ | 47.7% |
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 about half 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 | 71% |
| Credit spreads | 29% |
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 | +2.12 yr |
| High yield | +0.31 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 | 0.63 yr | 11% |
| 5 yr | 1.65 yr | 28% |
| 10 yr | 2.30 yr | 39% |
| 30 yr | 1.26 yr | 21% |
| 3 mo | 0.02 yr | 1% |
| 1 yr | 0.39 yr | 16% |
| 5 yr | 1.03 yr | 42% |
| 10 yr | 0.75 yr | 31% |
| 30 yr | 0.25 yr | 10% |
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 | +0.01 | $12.5k | $5.0k |
| 1 yr | +0.63 | +0.29 | +0.10 | $239.7k | $84.5k |
| 5 yr | +1.65 | +0.87 | +0.16 | $718.6k | $132.3k |
| 10 yr | +2.30 | +0.71 | +0.04 | $586.1k | $30.4k |
| 30 yr | +1.26 | +0.24 | +0.01 | $197.5k | $5.1k |
Dollar change per 1bp of spread movement, as filed and sign-anchored. A blank cell was not filed; a zero was.
Holdings
By % of NAV · equity positions carry filed share counts · every resolvable issuer links to its company page
| Ticker | Issuer | %NAV | Value | Shares |
|---|---|---|---|---|
| — | United States of America4.13% · due 2027-02-15 | 3.28% | $270.86M | — |
| — | United States of America4.75% · due 2043-11-15 | 2.11% | $174.24M | — |
| — | United States of America4.25% · due 2029-06-30 | 2.04% | $168.59M | — |
| — | United States of America4.25% · due 2054-02-15 | 1.96% | $162.12M | — |
| — | MFS Institutional Money Market Portfolio | 1.53% | $126.45M | — |
| — | United States of America4.25% · due 2034-11-15 | 1.24% | $101.99M | — |
| — | United States of America4.38% · due 2043-08-15 | 1.15% | $95.27M | — |
| — | United States of America4.88% · due 2028-10-31 | 1.13% | $93.00M | — |
| — | United States of America4.50% · due 2054-11-15 | 1.12% | $92.29M | — |
| — | FHLMC Pool2.00% · due 2052-03-01 | 1.08% | $89.19M | — |
Top 10 positions are 16.64% of net assets, top 25 26.48%, across 224 issuers.
See more of this fund's book
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