ANCFX vs MGK: 32% overlap
American Funds Fundamental Investors A and Vanguard Mega Cap Growth ETF share 31.7% 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 3 months apart — ANCFX as of 2026-03-31, the rest through 2026-06-30. 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 1.7. Two funds that shared nothing would score 2.0; two identical funds score 1.0.
Top shared holdings
ANCFX and MGK hold 28 of the same securities. The ten contributing most to the overlap figure:
| Holding | in ANCFX | in MGK | Δ |
|---|---|---|---|
| MSFT | 4.5% | 7.5% | 3.0% |
| AVGO | 5.9% | 4.3% | 1.7% |
| GOOG | 3.6% | 4.6% | 1.0% |
| NVDA | 3.6% | 13.2% | 9.6% |
| AMZN | 2.8% | 4.4% | 1.6% |
| META | 2.3% | 4.1% | 1.8% |
| GOOGL | 1.6% | 5.9% | 4.3% |
| AAPL | 1.5% | 12.1% | 10.6% |
| V | 1.2% | 1.8% | 0.6% |
| KLAC | 1.2% | 1.5% | 0.3% |
Where ANCFX and MGK 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 | MGK | Δ |
|---|---|---|---|
| Information Technology | 27.8% | 58.6% | −30.8pp |
| Industrials | 12.0% | 2.6% | +9.4pp |
| Unclassified | 9.3% | 0.0% | +9.3pp |
| Consumer Staples | 9.4% | 0.4% | +9.0pp |
| Communication Services | 9.0% | 16.2% | −7.3pp |
| Financials | 8.1% | 4.0% | +4.2pp |
| Consumer Discretionary | 8.9% | 11.2% | −2.3pp |
| Energy | 2.3% | 0.0% | +2.3pp |
Δ is ANCFX minus MGK, 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
65.6% of ANCFX by weight, held in no part of MGK.
21.2% of MGK 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 | MGK | |
|---|---|---|
| Top 10 holdings | 34.1% | 63.5% |
| Positions held | 233 | 57 |
| Cost per $10,000 held, per year | $61 | $5 |
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 MGK overlap?
ANCFX and MGK overlap 31.7% by portfolio weight — moderate overlap. They share 28 holdings. The figure comes from current issuer holdings files (ANCFX as of 2026-03-31, MGK as of 2026-06-30).
How is the overlap between ANCFX and MGK 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 MGK 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 MGK?
That depends on your goals — we state facts, not advice. At 31.7% overlap, each fund still contributes meaningfully distinct exposure.
What does ANCFX own that MGK doesn't?
ANCFX holds 233 positions and MGK holds 57; 204 of ANCFX's positions don't appear in MGK at all, and they are 65.6% of ANCFX by weight.
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Related comparisons
Sources: issuer holdings files, ANCFX as of 2026-03-31, MGK as of 2026-06-30. Weights are fractions of each fund. Diagnostics, not advice.