MFS Blended Research Mid Cap Equity Fund
Actively managed U.S. stock fund
As of its 2026 Q2 report, MFS Blended Research Mid Cap Equity Fund held 160 positions with $2.93B in net assets. Its ten largest holdings made up 19.9% of the fund. The BMSFX share class costs 0.84% a year. Over the 12 months to May 2026, BMSFX returned 20.8%, with dividends reinvested. In 2026 Q2 it added 26 new positions and exited 16.
The funds investment objective is to seek capital appreciation.
The fund invests at least 80% of assets in mid-capitalization equities selected through a blend of fundamental and quantitative analysis, with portfolio construction guided by a target tracking error of approximately 3% relative to the Russell Midcap Index. The fund's active approach is unconstrained by investment style, allowing exposure to growth stocks, value stocks, or combinations thereof, and may concentrate meaningfully in single industries or sectors. Because the fund's returns depend on the quality of its security selection rather than index replication, performance may diverge materially from the Russell Midcap Index.
What you own
| Company | Weight | Value | Shares | Reported price |
|---|---|---|---|---|
2.94% | $86.43M | 162.7K | $531.21 | |
Flex Ltd. | 2.67% | $78.42M | 520.1K | $150.78 |
1.99% | $58.27M | 238.0K | $244.82 | |
CIENCiena Corp. | 1.90% | $55.75M | 96.1K | $580.23 |
Viking Holdings Ltd. | 1.86% | $54.51M | 591.8K | $92.11 |
OKTAOkta, Inc. | 1.82% | $53.48M | 433.9K | $123.27 |
1.76% | $51.56M | 311.6K | $165.45 | |
ARMKAramark | 1.70% | $49.97M | 936.2K | $53.38 |
1.62% | $47.59M | 182.2K | $261.16 | |
1.59% | $46.64M | 666.9K | $69.94 |
Reported price is the fund's own reported value divided by its own reported shares at 2026-05-31 — not a live quote, and not what the fund paid.
All 160 holdings, with the share counts as filed, open with a free account.
What the fund is made of
Percentages are of fund net assets. Rounding, liabilities and short positions can make totals differ from 100%.
| Stocks | 99.39% |
| Cash & short-term | 0.44% |
By sector
- Information Technology
- 17.7%
- Industrials
- 16.1%
- Financials
- 13.8%
- Health Care
- 10.2%
- 9 other sectors
- 42.1%
- Information Technology
- 17.7%
- Industrials
- 16.1%
- Financials
- 13.8%
- Health Care
- 10.2%
- Consumer Discretionary
- 8.7%
- Energy
- 6.4%
- Real Estate
- 6.3%
- Utilities
- 6.2%
- International
- 4.6%
- Materials
- 3.5%
- Communication Services
- 3.4%
- Consumer Staples
- 2.7%
- Cash
- 0.4%
How it has done
BMSFX share class · total returns with dividends reinvested
Volatility over the last 12 months: 12.01%. Past returns are a record, not a forecast.
The 9 share classes hold the same portfolio
| Share class | Expense ratio | 1 year | 3 years | 5 years | Worst fall |
|---|---|---|---|---|---|
| 0.84% | +20.81% | +71.13% | +62.14% | -13.22% | |
| 1.59% | +19.94% | +67.39% | +56.16% | -13.47% | |
| 1.59% | +19.92% | +67.26% | +56.20% | -13.46% | |
| 0.59% | +21.10% | +72.39% | +64.18% | -13.10% | |
| 1.59% | +20.82% | +69.43% | +58.18% | -13.23% | |
| 1.09% | +20.44% | +69.84% | +60.14% | -13.33% | |
| 0.84% | +20.85% | +71.19% | +62.22% | -13.23% | |
| 0.59% | +21.11% | +72.53% | +64.32% | -13.13% | |
| 0.52% | +21.19% | +72.89% | +65.03% | -13.10% |
These classes hold the same portfolio, so the 8.87pp spread over 5 years is the cost difference between them — roughly 1.77pp a year — not a difference in what they own.
Fees & fund details
MFS Blended Research Mid Cap Equity Fund is an actively managed U.S. equity fund. 13% of BMSFX’s stock holdings are in companies whose revenue grew in the top quartile of U.S. companies over the last five fiscal years (covering 88% of the fund’s equity).
- Asset class
- Equity
- Region
- United States
- Management
- Actively managed
- Fund type
- Open-end fund
- Expense ratio, by class
- 0.52% – 1.59%· BMSFX 0.84%
- Portfolio turnover
- 58.00% a year · as of 2025 Q3
Net is what a holder pays after the adviser's contractual waiver; gross is before it. A waiver can expire.
Turnover is how much of the portfolio was replaced in a year.
Classified from what the fund holds, not from its name · 2026 Q2. The summary is a paraphrase of the prospectus; the objective is verbatim.
What changed this quarter
Positions that entered or left the fund since its previous filing. Positions that were only resized are not listed.
26 new· the largest 8
16 exited· the largest 8
Understand how this fund fits with the rest.
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