MFS Core Equity Fund

MFS SERIES TRUST I · 9 share classes

Actively managed U.S. equity fund
One fund, 9 share classes:MRGAXMRGJXMRGBXMRGCXMRGRXMRGGXMRERXMRGHXMRGKX
$6.49B NAV
172 positions · as of 2026-05-31 · filed 2026-07-27

Fund classification

Classified from what the fund holds · as of 2026 Q2

MFS Core Equity Fund is an actively managed U.S. equity fund. 22% of MRGAX’s stock holdings are in companies whose revenue grew in the top quartile of U.S. companies over the last five fiscal years (covering 91% of the fund’s equity).

Asset class
Equity
Region
United States
Management
Actively managed
Fund type
Open-end fund

Fund profile

As filed in the prospectus · 2025 Q4

The funds investment objective is to seek capital appreciation.

Strategy · summarised

The fund invests at least 80% of assets in equity securities selected through fundamental analysis of individual companies, with a team of research analysts identifying stocks they believe offer above-average earnings growth or are undervalued relative to their perceived worth. The fund's broad industry exposure is expected to approximate that of the Russell 3000 Index, though MFS may concentrate a significant portion in a single industry or sector. The fund may hold securities of any size and may invest in foreign equities. Because the fund's returns depend on the security selections made by its research team, performance will diverge from the Russell 3000 Index.

Expenses
0.55% 1.63%across 9 share classes
Share classGrossNet
MRGAX0.89%0.88%
MRGJX0.64%0.63%
MRGBX1.64%1.63%
MRGCX1.64%1.63%
MRGRX0.64%0.63%
MRGGX1.64%1.63%
MRERX1.14%1.13%
MRGHX0.89%0.88%
MRGKX0.56%0.55%

Net is what a holder pays after the adviser's contractual waiver; gross is before it. A waiver can expire.

Portfolio turnover 43.00% · as of 2025 Q4

Allocation

Asset groups · long / short shown separately, never netted · 2026 Q2

100.43%
of net assets
Stocks99.92%
Cash & short-term0.51%

Sector allocation

The same holdings as Allocation above, grouped by market sector instead of asset type · as of 2026 Q2

100%
of net assets
Information Technology33.0%
Industrials11.0%
Financials10.7%
Communication Services9.9%
10 smaller35.5%

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).

Portfolio growth profile

How much of the fund’s stock holdings are in fast-growing companies · as of 2026 Q2

Revenue growth
22%of stock holdings in top-quartile growers
covering 91% of the fund’s equity
Earnings growth
31%of stock holdings in top-quartile growers
covering 83% of the fund’s equity

Share of the fund’s equity (by value) in companies whose trailing five-year revenue — or net-income — growth ranks in the top 25% of U.S. public companies. Foreign and newly-listed holdings are excluded, so the figure covers only part of the book. From SEC filings — not investment advice. How we measure this.

Latest quarter

What changed since the fund's previous filing

2026Q2 vs 2026Q1: 21 new18 exited

Largest new: MU, SNDK, HON, VRTX, NFLX, SSD, ADI, DOCN

Largest exited: LRCX, Eaton Corp PLC, MCK, PG, PHM, TYL, DIS, HUBS

Return profile

Chart:

Total return as filed — price change plus distributions reinvested · trailing figures to Apr 2026

Share class1-year3-year5-yearVolWorst fall
+24.44%+61.85%+61.23%12.37%-9.34%
+24.72%+62.99%+63.21%12.36%-9.29%
+23.49%+58.22%+55.22%12.35%-9.52%
+23.47%+58.16%+55.21%12.36%-9.51%
+24.72%+63.03%+63.25%12.36%-9.29%
+23.47%+58.17%+55.20%12.36%-9.51%
+24.08%+60.59%+59.26%12.33%-9.38%
+24.42%+61.82%+61.27%12.36%-9.33%
+24.84%+63.41%+63.90%12.37%-9.28%

These classes hold the same portfolio, so the 8.69pp spread over 5 years is the cost difference between them — roughly 1.74pp a year — not a difference in what they own.

Cumulative return· Jun 2023 – Apr 2026

May 2026 has been filed since the trailing figures were struck, so it is not in the table above or the curve — every figure here shares one cut-off, which is what makes them comparable with other funds.

Holdings

By % of NAV · equity positions carry filed share counts · every resolvable issuer links to its company page

Issuer%NAVValue
NVIDIA CorpNVDA7.73%$501.30M
Apple IncAAPL6.13%$397.69M
Alphabet IncGOOGL5.38%$349.02M
Microsoft CorpMSFT5.10%$330.76M
Amazon.com IncAMZN5.09%$330.31M
Broadcom IncAVGO3.80%$246.33M
Meta Platforms IncMETA2.50%$162.50M
JPMorgan Chase & CoJPM1.83%$118.58M
Arista Networks IncANET1.73%$112.22M
Pfizer IncPFE1.47%$95.30M
Showing 10 of 172Sign in to see more

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.

Top 10 positions are 40.76% of net assets, top 25 55.14%, across 172 issuers.

See more of this fund's book

More positions with filed share counts, and the quarter-over-quarter change list rather than the largest few — free with an account, no card required.

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