BMSTX Performance — MFS Blended Research Mid Cap Equity Fund, Class R3
Data updated: 2026-09-25
BMSTX returned +12.44% year to date and +20.85% over one year to May 2026. Annualised returns are +19.63% over 3 years and +10.16% over 5 years. Against its US Mid-Cap Blend category average the fund came out ahead over three years but behind over one: $100 invested three years ago grew to $171, against $156 for the category, and to $121 over one year, against $122. Volatility over the past three years was 16.33% a year. In the 12 months to May 2026 the fund took in a net $1.1B, and assets reached $2.93B.
BMSTX Growth of $100
What $100 invested in MFS Blended Research Mid Cap Equity Fund grew to, compounded from monthly returns reported on SEC Form N-PORT, against the US Mid-Cap Blend category average over the same months.
| Period | BMSTX | Category average |
|---|---|---|
| 1 year (Jun 2025 – May 2026) | $121 | $122 |
| 3 years (Jun 2023 – May 2026) | $171 | $156 |
| 5 years (Jun 2021 – May 2026) | $162 | $143 |
| Since data start (Sep 2019 – May 2026) | $224 | $204 |
BMSTX Trailing Returns
Total returns to May 2026, from SEC N-PORT.
| Period | Total return |
|---|---|
| YTD | +12.44% |
| 1 year | +20.85% |
| 3 years (annualised) | +19.63% |
| 5 years (annualised) | +10.16% |
BMSTX Annual Returns
Calendar-year total returns of MFS Blended Research Mid Cap Equity Fund, compounded from monthly SEC N-PORT returns. Partial years show the months covered.
| Year | Total return |
|---|---|
| 2026 (Jan–May) | +12.44% |
| 2025 | +7.70% |
| 2024 | +19.07% |
| 2023 | +19.35% |
| 2022 | −13.88% |
| 2021 | +26.39% |
| 2020 | +10.18% |
| 2019 (Sep–Dec) | +8.29% |
BMSTX Monthly Returns
Monthly total returns as reported on SEC Form N-PORT.
| Year | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2026 | +3.2% | +3.1% | −5.7% | +8.4% | +3.4% | — | — | — | — | — | — | — |
| 2025 | +4.9% | −3.6% | −4.4% | −2.8% | +6.6% | +3.5% | +1.0% | +3.7% | +0.7% | −2.2% | +1.1% | −0.3% |
| 2024 | +0.5% | +5.0% | +6.1% | −4.7% | +3.8% | −1.2% | +5.1% | +1.3% | +2.4% | −0.6% | +8.6% | −7.7% |
| 2023 | +8.7% | −1.6% | −2.4% | −0.9% | −2.8% | +9.3% | +3.3% | −2.6% | −4.6% | −5.3% | +10.4% | +8.1% |
| 2022 | −6.2% | −0.9% | +2.2% | −6.1% | +1.5% | −9.3% | +8.7% | −3.2% | −8.1% | +11.2% | +3.0% | −5.2% |
| 2021 | −0.7% | +4.5% | +4.9% | +5.7% | +0.4% | +1.3% | +1.7% | +2.6% | −4.2% | +5.5% | −2.9% | +5.4% |
| 2020 | −0.6% | −9.3% | −19.1% | +13.2% | +6.6% | +0.8% | +6.1% | +2.6% | −3.1% | −0.7% | +12.3% | +5.7% |
| 2019 | — | — | — | — | — | — | — | — | +1.9% | +1.2% | +3.4% | +1.6% |
BMSTX Risk
Risk measures from monthly returns over Jun 2023 – May 2026.
- 3-year volatility (annualised): 16.33%
- 3-year Sharpe ratio: 0.93 (vs 4.5% risk-free rate)
- Best month: +10.38% (Nov 2023)
- Worst month: −7.66% (Dec 2024)
BMSTX Fund Flows
Monthly money in and out of MFS Blended Research Mid Cap Equity Fund, from SEC Form N-PORT.
- 12-month net flow: $1.1B
- 12-month gross sales (incl. reinvestments): $1.7B
- Sales ÷ redemptions: 2.81×
| Month | Sales | Redemptions | Net flow |
|---|---|---|---|
| May 2026 | $234.3M | $126.3M | $108.0M |
| Apr 2026 | $74.0M | $62.3M | $11.7M |
| Mar 2026 | $143.0M | $49.1M | $93.8M |
| Feb 2026 | $88.0M | $45.9M | $42.2M |
| Jan 2026 | $111.5M | $53.5M | $58.1M |
| Dec 2025 | $140.9M | $49.4M | $91.5M |
| Nov 2025 | $126.4M | $67.6M | $58.9M |
| Oct 2025 | $142.9M | $37.8M | $105.1M |
| Sep 2025 | $237.1M | $19.3M | $217.8M |
| Aug 2025 | $148.1M | $22.8M | $125.3M |
| Jul 2025 | $89.3M | $31.1M | $58.2M |
| Jun 2025 | $114.6M | $21.7M | $92.8M |
BMSTX Assets Under Management
Net assets of MFS Blended Research Mid Cap Equity Fund by report date, from SEC N-PORT filings.
| Report date | Net assets |
|---|---|
| 2026-05-31 | $2.93B |
| 2026-02-28 | $2.56B |
| 2025-11-30 | $2.29B |
| 2025-08-31 | $1.92B |
| 2025-05-31 | $1.50B |
| 2025-02-28 | $1.19B |
| 2024-11-30 | $955.35M |
| 2024-08-31 | $794.90M |
| 2024-05-31 | $698.85M |
| 2024-02-29 | $615.24M |
| 2023-11-30 | $548.04M |
| 2023-08-31 | $541.77M |
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.