BRSBX Performance — MFS Blended Research Small Cap Equity Fund, Class B
Data updated: 2026-09-25
BRSBX returned +13.62% year to date and +31.44% over one year to May 2026. Annualised returns are +14.04% over 3 years and +4.30% over 5 years. The fund trailed its US Small Blend category average: $100 invested three years ago grew to $148, against $160 for the category, and to $131 over one year, against $132. Volatility over the past three years was 19.19% a year. In the 12 months to May 2026 the fund lost a net $49.0M, and assets reached $326.51M.
BRSBX Growth of $100
What $100 invested in MFS Blended Research Small Cap Equity Fund grew to, compounded from monthly returns reported on SEC Form N-PORT, against the US Small Blend category average over the same months.
| Period | BRSBX | Category average |
|---|---|---|
| 1 year (Jun 2025 – May 2026) | $131 | $132 |
| 3 years (Jun 2023 – May 2026) | $148 | $160 |
| 5 years (Jun 2021 – May 2026) | $123 | $135 |
| Since data start (Sep 2019 – May 2026) | $171 | $206 |
BRSBX Trailing Returns
Total returns to May 2026, from SEC N-PORT.
| Period | Total return |
|---|---|
| YTD | +13.62% |
| 1 year | +31.44% |
| 3 years (annualised) | +14.04% |
| 5 years (annualised) | +4.30% |
BRSBX Annual Returns
Calendar-year total returns of MFS Blended Research Small Cap Equity Fund, compounded from monthly SEC N-PORT returns. Partial years show the months covered.
| Year | Total return |
|---|---|
| 2026 (Jan–May) | +13.62% |
| 2025 | +4.70% |
| 2024 | +3.78% |
| 2023 | +17.60% |
| 2022 | −19.25% |
| 2021 | +27.82% |
| 2020 | +1.06% |
| 2019 (Sep–Dec) | +13.04% |
BRSBX 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 | +4.5% | +2.4% | −5.9% | +12.1% | +0.6% | — | — | — | — | — | — | — |
| 2025 | +1.8% | −4.3% | −7.9% | −4.3% | +5.4% | +5.2% | +0.8% | +7.3% | +0.5% | −0.4% | +2.1% | −0.5% |
| 2024 | −1.9% | +3.2% | +2.3% | −6.3% | +3.4% | −1.5% | +8.8% | −2.5% | −0.1% | −1.5% | +8.7% | −7.5% |
| 2023 | +9.3% | −1.6% | −5.7% | −1.5% | −2.0% | +9.2% | +5.6% | −3.5% | −4.9% | −6.6% | +8.6% | +12.0% |
| 2022 | −7.2% | +1.8% | +0.9% | −8.9% | +0.4% | −8.9% | +9.5% | −4.4% | −9.0% | +10.7% | +2.8% | −6.2% |
| 2021 | +4.6% | +7.6% | +2.8% | +4.0% | +0.9% | +0.8% | −1.5% | +3.8% | −2.6% | +4.0% | −3.5% | +4.5% |
| 2020 | −5.0% | −9.5% | −22.9% | +13.7% | +5.3% | +1.4% | +2.9% | +3.5% | −4.5% | +1.7% | +13.8% | +6.6% |
| 2019 | — | — | — | — | — | — | — | — | +1.7% | +2.7% | +5.1% | +3.1% |
BRSBX Risk
Risk measures from monthly returns over Jun 2023 – May 2026.
- 3-year volatility (annualised): 19.19%
- 3-year Sharpe ratio: 0.50 (vs 4.5% risk-free rate)
- Best month: +12.08% (Apr 2026)
- Worst month: −7.86% (Mar 2025)
BRSBX Fund Flows
Monthly money in and out of MFS Blended Research Small Cap Equity Fund, from SEC Form N-PORT.
- 12-month net flow: −$49.0M
- 12-month gross sales (incl. reinvestments): $57.3M
- Sales ÷ redemptions: 0.54×
| Month | Sales | Redemptions | Net flow |
|---|---|---|---|
| May 2026 | $3.3M | $7.6M | −$4.2M |
| Apr 2026 | $2.6M | $6.7M | −$4.2M |
| Mar 2026 | $5.1M | $10.9M | −$5.8M |
| Feb 2026 | $2.5M | $4.6M | −$2.2M |
| Jan 2026 | $2.9M | $10.6M | −$7.7M |
| Dec 2025 | $23.5M | $8.0M | $15.5M |
| Nov 2025 | $3.4M | $5.9M | −$2.6M |
| Oct 2025 | $2.9M | $5.1M | −$2.2M |
| Sep 2025 | $2.6M | $17.9M | −$15.2M |
| Aug 2025 | $3.5M | $8.5M | −$5.0M |
| Jul 2025 | $2.9M | $14.5M | −$11.6M |
| Jun 2025 | $2.2M | $6.0M | −$3.8M |
BRSBX Assets Under Management
Net assets of MFS Blended Research Small Cap Equity Fund by report date, from SEC N-PORT filings.
| Report date | Net assets |
|---|---|
| 2026-05-31 | $326.51M |
| 2026-02-28 | $320.96M |
| 2025-11-30 | $313.92M |
| 2025-08-31 | $326.61M |
| 2025-05-31 | $304.97M |
| 2025-02-28 | $327.19M |
| 2024-11-30 | $364.15M |
| 2024-08-31 | $347.50M |
| 2024-05-31 | $340.18M |
| 2024-02-29 | $325.69M |
| 2023-11-30 | $295.83M |
| 2023-08-31 | $312.96M |
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.