ANCFX vs MDY: 3% overlap
American Funds Fundamental Investors A and SPDR S&P MidCap 400 ETF Trust share 3.4% 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 — ANCFX 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
ANCFX and MDY hold 17 of the same securities. The ten contributing most to the overlap figure:
| Holding | in ANCFX | in MDY | Δ |
|---|---|---|---|
| ITT | 0.5% | 0.5% | 0.0% |
| PFGC | 0.6% | 0.5% | 0.1% |
| BURL | 0.4% | 0.6% | 0.2% |
| XPO | 0.3% | 0.7% | 0.4% |
| RNR | 0.3% | 0.4% | 0.1% |
| RGLD | 0.3% | 0.5% | 0.2% |
| JAZZ | 0.3% | 0.4% | 0.2% |
| SPXC | 0.2% | 0.3% | 0.1% |
| REXR | 0.1% | 0.2% | 0.1% |
| VNOM | 0.1% | 0.2% | 0.1% |
Where ANCFX and MDY 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 | ANCFX | MDY | Δ |
|---|---|---|---|
| Information Technology | 27.8% | 13.8% | +14.0pp |
| Industrials | 12.0% | 25.4% | −13.4pp |
| Unclassified | 9.3% | 0.0% | +9.3pp |
| Communication Services | 9.0% | 1.5% | +7.4pp |
| Financials | 8.1% | 14.8% | −6.7pp |
| Consumer Staples | 9.4% | 3.1% | +6.3pp |
| Real Estate | 1.8% | 6.9% | −5.1pp |
| Health Care | 6.2% | 9.7% | −3.5pp |
Δ is ANCFX minus MDY, 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
95.7% of ANCFX by weight, held in no part of MDY.
92.1% of MDY by weight, held in no part of ANCFX.
A large count with a small weight is the usual shape: the positions one fund adds are typically its smallest ones.
Concentration and cost
| ANCFX | MDY | |
|---|---|---|
| Top 10 holdings | 34.1% | 7.6% |
| Positions held | 233 | 400 |
| Cost per $10,000 held, per year | $61 | $23 |
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 ANCFX and MDY overlap?
ANCFX and MDY overlap 3.4% by portfolio weight — largely distinct portfolios. They share 17 holdings. The figure comes from current issuer holdings files (ANCFX as of 2026-03-31, MDY as of 2026-07-23).
How is the overlap between ANCFX and MDY calculated?
As the sum of the smaller weight in each fund, over every holding both funds own: Σ min(wA, wB). If ANCFX holds a stock at 6% and MDY 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 ANCFX and MDY?
That depends on your goals — we state facts, not advice. At 3.4% overlap, each fund still contributes meaningfully distinct exposure.
What does ANCFX own that MDY doesn't?
ANCFX holds 233 positions and MDY holds 400; 215 of ANCFX's positions don't appear in MDY at all, and they are 95.7% of ANCFX by weight.
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Related comparisons
Sources: issuer holdings files, ANCFX as of 2026-03-31, MDY as of 2026-07-23. Weights are fractions of each fund. Diagnostics, not advice.