FXAIX vs TSPC: 88% overlap
Fidelity 500 Index and TSP C Fund — shown via S&P 500 proxy share 88.3% 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 — FXAIX as of 2026-02-28, 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 1.1. Two funds that shared nothing would score 2.0; two identical funds score 1.0.
Top shared holdings
FXAIX and TSPC hold 463 of the same securities. The ten contributing most to the overlap figure:
| Holding | in FXAIX | in TSPC | Δ |
|---|---|---|---|
| NVDA | 7.3% | 7.5% | 0.2% |
| AAPL | 6.6% | 6.6% | 0.0% |
| MSFT | 5.0% | 4.3% | 0.7% |
| AMZN | 3.5% | 3.6% | 0.1% |
| GOOGL | 3.1% | 3.2% | 0.2% |
| AVGO | 2.6% | 2.8% | 0.2% |
| GOOG | 2.5% | 2.6% | 0.1% |
| META | 2.4% | 1.9% | 0.5% |
| TSLA | 1.9% | 1.8% | 0.1% |
| BRK-B | 1.6% | 1.4% | 0.2% |
Where FXAIX and TSPC 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 | FXAIX | TSPC | Δ |
|---|---|---|---|
| Information Technology | 31.8% | 38.0% | −6.2pp |
| Unclassified | 3.3% | 0.0% | +3.3pp |
| Communication Services | 10.5% | 9.7% | +0.8pp |
| Consumer Staples | 5.4% | 4.6% | +0.8pp |
| Health Care | 9.6% | 8.9% | +0.7pp |
| Industrials | 8.3% | 8.9% | −0.6pp |
| Energy | 3.4% | 3.0% | +0.5pp |
| Financials | 12.0% | 11.6% | +0.4pp |
Δ is FXAIX minus TSPC, 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
3.5% of FXAIX by weight, held in no part of TSPC.
4.1% of TSPC by weight, held in no part of FXAIX.
A large count with a small weight is the usual shape: the positions one fund adds are typically its smallest ones.
Concentration and cost
| FXAIX | TSPC | |
|---|---|---|
| Top 10 holdings | 36.4% | 36.4% |
| Positions held | 506 | 505 |
| Cost per $10,000 held, per year | $1 | $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 FXAIX and TSPC overlap?
FXAIX and TSPC overlap 88.3% by portfolio weight — substantial duplication if you hold both. They share 463 holdings. The figure comes from current issuer holdings files (FXAIX as of 2026-02-28, TSPC as of 2026-06-30).
How is the overlap between FXAIX and TSPC calculated?
As the sum of the smaller weight in each fund, over every holding both funds own: Σ min(wA, wB). If FXAIX holds a stock at 6% and TSPC 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 FXAIX and TSPC?
That depends on your goals — we state facts, not advice. At 88.3% overlap, most of what one fund holds, the other holds too. Expense ratios: FXAIX 0.01% versus TSPC 0.05%.
What does FXAIX own that TSPC doesn't?
FXAIX holds 506 positions and TSPC holds 505; 42 of FXAIX's positions don't appear in TSPC at all, and they are 3.5% of FXAIX by weight.
You probably hold more than two funds
This page compares FXAIX and TSPC. 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 FXAIX vs TSPC
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, FXAIX as of 2026-02-28, TSPC as of 2026-06-30. Weights are fractions of each fund. Diagnostics, not advice.