MDY vs PRGFX: 0% overlap
SPDR S&P MidCap 400 ETF Trust and T. Rowe Price Growth Stock share 0.1% of their portfolios by weight — computed as Σ min(wA, wB) over every holding both funds own.
Different holding dates. These holdings were published about 4 months apart — PRGFX as of 2026-03-31, the rest through 2026-07-23. Each fund is compared using its most recent file, so any trading in between shows up as a difference.
You would hold two tickers and get the diversification of 2.0. Two funds that shared nothing would score 2.0; two identical funds score 1.0.
Top shared holdings
MDY and PRGFX hold 1 of the same securities. The ten contributing most to the overlap figure:
| Holding | in MDY | in PRGFX | Δ |
|---|---|---|---|
| WING | 0.1% | 0.1% | 0.0% |
Where MDY and PRGFX differ
Sector weights as a share of each fund, ordered by the size of the gap rather than the size of the sector — two funds that overlap heavily still usually diverge somewhere.
| Sector | MDY | PRGFX | Δ |
|---|---|---|---|
| Information Technology | 13.8% | 48.2% | −34.4pp |
| Industrials | 25.4% | 5.6% | +19.8pp |
| Communication Services | 1.5% | 13.1% | −11.6pp |
| Financials | 14.8% | 5.1% | +9.7pp |
| Real Estate | 6.9% | 0.5% | +6.3pp |
| Unclassified | 0.0% | 5.9% | −5.9pp |
| Materials | 5.4% | 0.2% | +5.2pp |
| Energy | 4.9% | 0.0% | +4.9pp |
Δ is MDY minus PRGFX, in percentage points. Sector data is not published by every issuer, so “Unclassified” is a real category rather than a gap in the table.
What each fund holds alone
98.8% of MDY by weight, held in no part of PRGFX.
96.6% of PRGFX by weight, held in no part of MDY.
A large count with a small weight is the usual shape: the positions one fund adds are typically its smallest ones.
Concentration and cost
| MDY | PRGFX | |
|---|---|---|
| Top 10 holdings | 7.6% | 62.8% |
| Positions held | 400 | 79 |
| Cost per $10,000 held, per year | $23 | $64 |
Cost is the expense ratio applied to $10,000; it excludes any brokerage commission, bid-ask spread or tax consequence. Figures are facts about the funds, not a suggestion about which to hold.
Frequently asked
How much do MDY and PRGFX overlap?
MDY and PRGFX overlap 0.1% by portfolio weight — largely distinct portfolios. They share 1 holdings. The figure comes from current issuer holdings files (MDY as of 2026-07-23, PRGFX as of 2026-03-31).
How is the overlap between MDY and PRGFX calculated?
As the sum of the smaller weight in each fund, over every holding both funds own: Σ min(wA, wB). If MDY holds a stock at 6% and PRGFX holds the same stock at 4%, 4% counts as shared. The result is bounded between 0% and 100%, and it is computed after looking through any fund-of-funds to the underlying holdings.
Is it redundant to hold both MDY and PRGFX?
That depends on your goals — we state facts, not advice. At 0.1% overlap, each fund still contributes meaningfully distinct exposure.
What does MDY own that PRGFX doesn't?
MDY holds 400 positions and PRGFX holds 79; 398 of MDY's positions don't appear in PRGFX at all, and they are 98.8% of MDY by weight.
You probably hold more than two funds
This page compares MDY and PRGFX. Paste your whole portfolio — brokerage, 401(k), IRA — and see the overlap across every fund at once, plus what you actually own underneath them and your own Effective Funds number. Free, no account, nothing stored.
X-ray my portfolio — free →Watch MDY vs PRGFX
We re-read both funds’ published holdings every weeknight. Leave an address and we'll tell you when what's inside actually changes.
Not sending yet — email alerts are built but switched off, and you'll be among the first when they turn on. No spam, one-click unsubscribe.
Related comparisons
Sources: issuer holdings files, MDY as of 2026-07-23, PRGFX as of 2026-03-31. Weights are fractions of each fund. Diagnostics, not advice.