AIVSX vs VIMAX: 8% overlap
American Funds Investment Company of America A and Vanguard Mid-Cap Index Admiral share 7.7% 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 — AIVSX 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 1.9. Two funds that shared nothing would score 2.0; two identical funds score 1.0.
Top shared holdings
AIVSX and VIMAX hold 40 of the same securities. The ten contributing most to the overlap figure:
| Holding | in AIVSX | in VIMAX | Δ |
|---|---|---|---|
| RCL | 1.9% | 0.7% | 1.2% |
| CARR | 1.1% | 0.6% | 0.5% |
| URI | 0.4% | 0.7% | 0.3% |
| ALNY | 0.4% | 0.4% | 0.0% |
| D | 0.4% | 0.6% | 0.2% |
| FANG | 0.3% | 0.3% | 0.0% |
| IR | 0.5% | 0.3% | 0.2% |
| XEL | 0.3% | 0.5% | 0.2% |
| GEHC | 0.5% | 0.3% | 0.3% |
| CNP | 0.4% | 0.3% | 0.1% |
Where AIVSX and VIMAX 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 | AIVSX | VIMAX | Δ |
|---|---|---|---|
| Information Technology | 29.2% | 16.1% | +13.1pp |
| Industrials | 11.8% | 19.6% | −7.8pp |
| Communication Services | 9.9% | 2.8% | +7.1pp |
| Utilities | 2.3% | 8.4% | −6.1pp |
| Financials | 8.2% | 14.0% | −5.9pp |
| Energy | 1.9% | 7.3% | −5.4pp |
| Unclassified | 5.5% | 0.4% | +5.1pp |
| Real Estate | 0.8% | 5.1% | −4.3pp |
Δ is AIVSX minus VIMAX, 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
89.0% of AIVSX by weight, held in no part of VIMAX.
84.3% of VIMAX by weight, held in no part of AIVSX.
A large count with a small weight is the usual shape: the positions one fund adds are typically its smallest ones.
Concentration and cost
| AIVSX | VIMAX | |
|---|---|---|
| Top 10 holdings | 39.5% | 9.5% |
| Positions held | 168 | 283 |
| Cost per $10,000 held, per year | $58 | $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 AIVSX and VIMAX overlap?
AIVSX and VIMAX overlap 7.7% by portfolio weight — largely distinct portfolios. They share 40 holdings. The figure comes from current issuer holdings files (AIVSX as of 2026-03-31, VIMAX as of 2026-06-30).
How is the overlap between AIVSX and VIMAX calculated?
As the sum of the smaller weight in each fund, over every holding both funds own: Σ min(wA, wB). If AIVSX holds a stock at 6% and VIMAX 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 AIVSX and VIMAX?
That depends on your goals — we state facts, not advice. At 7.7% overlap, each fund still contributes meaningfully distinct exposure.
What does AIVSX own that VIMAX doesn't?
AIVSX holds 168 positions and VIMAX holds 283; 128 of AIVSX's positions don't appear in VIMAX at all, and they are 89.0% of AIVSX by weight.
You probably hold more than two funds
This page compares AIVSX and VIMAX. 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 AIVSX vs VIMAX
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, AIVSX as of 2026-03-31, VIMAX as of 2026-06-30. Weights are fractions of each fund. Diagnostics, not advice.