Wealthy PotFXAIX vs VT: The S&P 500 Is 55% of VT, and the Other 45% Is the Real Question
FXAIX and VT are not two ways to buy the same thing. FXAIX is Fidelity's S&P 500 index mutual fund: about 500 large US companies for 0.015% a year. VT is Vanguard's Total World Stock ETF: about 10,000 companies across developed and emerging markets for 0.06%, with 62% of its stocks in the US. Matching their latest SEC holdings filings, the overlap was 55.1%. Nearly all of FXAIX sits inside VT, but 45% of VT is something FXAIX does not own at all. The choice is whether you want to own the rest of the world.
Table of Contents
The Short Answer
- Fees: 0.015% vs 0.06%. On $10,000 that is $1.50 against $6 a year; on $100,000, $15 against $60.
- Overlap: 55.1%. 99.8% of FXAIX sat in companies VT also held; only 55.1% of VT sat in FXAIX's companies. Our calculation from FXAIX's 31 May 2026 and VT's 31 July 2026 N-PORT filings.
- What VT adds: about 38% outside the US (Japan, Taiwan, the UK, Canada and more) plus US mid and small companies. VT was 62.0% US on 31 August 2026.
- Returns to 30 September 2026: FXAIX 15.32% a year over 10 years, VT 12.32%. Over 1 year VT led, 16.32% to 15.72%.
- Wrapper: FXAIX is a mutual fund with no minimum, bought at the day's closing price through Fidelity or an investment professional. VT is an ETF that trades at any brokerage.
- Hold both? Possible, but it tilts VT's mix further toward US large caps. Decide your US share first.
How Much of VT Is the S&P 500
| Portfolios in the latest N-PORT filings | FXAIX (31 May 2026) | VT (31 Jul 2026) |
|---|---|---|
| Companies in the filing | 501 | 9,682 |
| Held by both funds | 497 | 497 |
| Share of the fund in those shared companies | 99.8% | 55.1% |
| Companies the other fund did not own | 4 (0.03% of FXAIX) | 9,185 (44.1% of VT) |
| Top-10 weight | 40.6% | 22.3% |
| Overlap, sum of the smaller weight in each shared stock | 55.1% | |
The same companies lead both funds, at roughly half the weight in VT. NVIDIA was 7.89% of FXAIX and 4.06% of VT; Apple 7.05% against 3.87%; Microsoft 5.14% against 2.99%. If you own VT, about 55 cents of each dollar is in the S&P 500 already. Most of the remaining 45 cents is outside the US, and the gap between that and VT's 62% US share is US mid and small companies the S&P 500 leaves out.
That also explains the concentration gap. FXAIX's ten biggest holdings were about 41% of the fund. VT's were about 22%, and Vanguard's own fact sheet put VT's top ten at 21.7% on 30 June 2026.
FXAIX vs VT Side by Side
| FXAIX | VT | |
|---|---|---|
| Full name | Fidelity 500 Index Fund | Vanguard Total World Stock ETF |
| Index | S&P 500 | FTSE Global All Cap Index |
| What it covers | Large US companies | Large, mid and small companies in developed and emerging markets, US included |
| Expense ratio | 0.015% | 0.06% |
| Cost on $10,000 over 10 years (prospectus example) | $19 | $77 |
| Stocks held | 501 (N-PORT, 31 May 2026) | 10,088 (Vanguard, 31 Aug 2026) |
| US share | All US | 62.0% (31 Aug 2026) |
| Portfolio turnover, latest fiscal year | 3% | 3% |
| Size | $857.6 billion share class (Fidelity, 30 Sep 2026) | $101.7 billion fund (31 Aug 2026) |
| Fund type | Mutual fund, priced once a day | ETF, trades all day at market price |
| Minimum | None | None set by the fund; one share or a fraction if your broker allows |
| Inception | 17 Feb 1988 | 24 Jun 2008 |
Returns: A Decade of US Leadership
| Average annual return to 30 Sep 2026 | 1 year | 3 years | 5 years | 10 years |
|---|---|---|---|---|
| FXAIX | 15.72% | 22.87% | 13.78% | 15.32% |
| S&P 500 | 15.74 | 22.89 | 13.79 | 15.33 |
| VT (NAV) | 16.32% | 21.42% | 11.34% | 12.32% |
| Spliced Total World Stock Index | 16.57 | 21.48 | 11.39 | 12.40 |
| FXAIX minus VT | -0.60 | +1.45 | +2.44 | +3.00 |
Over three, five and ten years, the US large companies that make up FXAIX beat the rest of the world, and VT carried the rest of the world. Over the latest year it went the other way. The prospectus numbers to 31 December 2025 show the same swing: in calendar 2025, VT returned 22.44% and FXAIX 17.86%, while over the ten years to that date FXAIX led 14.81% to 11.78% a year.
| Hypothetical $10,000 held 10 years | Ending value |
|---|---|
| At FXAIX's 10-year return (15.32%) | $41,595 |
| At VT's 10-year return (12.32%) | $31,957 |
That $9,638 gap is a record of one decade, not a forecast. Whether US stocks keep outrunning everyone else is the bet you make by choosing FXAIX, and VT is the fund for people who would rather not make it. The fee gap of 0.045 points a year is tiny next to either outcome.
This is educational information, not personalized investment advice. Past performance does not guarantee future results, and all investing carries the risk of loss.
Where They Differ Beyond Geography
Mutual fund vs ETF. FXAIX's prospectus says you may buy it "through a Fidelity® brokerage or mutual fund account, through a retirement account, or through an investment professional", with no purchase minimum. You buy in exact dollar amounts at the closing price, which suits automatic monthly investing. Outside Fidelity, check what your broker charges to buy it. VT trades like a stock at any brokerage, including Fidelity, at a market price that can sit slightly above or below its net asset value.
401(k) menus. Workplace plans choose their own menus, and an S&P 500 index fund such as FXAIX is a common core option. If your 401(k) offers FXAIX and not a world fund, you can hold it there and get your international exposure in an IRA or taxable account, judging the split across all accounts.
Taxes in a brokerage account. Fidelity's history table shows no capital gain distributions from FXAIX in 2020 through 2026 so far; the last was $0.119 a share in 2019. VT's ETF shares paid none in fiscal 2021 through 2025, per Vanguard's financial highlights. After-tax returns in the prospectuses to 2025 show a slightly larger 10-year tax drag for VT (0.63 points) than FXAIX (0.51). VT's prospectus allows a foreign tax credit pass-through only when more than 50% of the fund is in foreign companies; at 62% US, VT does not meet that test.
Which One Fits You
You want one fund and the whole world in it: VT. It is a complete stock allocation in one ticker, it rebalances between countries by itself, and you can hold it at any broker.
You want US large companies only, at Fidelity or in a 401(k) that offers it: FXAIX. It costs 0.015% and has no minimum. Just know that it leaves out every company outside the US and every US company outside the 500.
You want international stocks but also the lowest fees at Fidelity: FXAIX plus a separate international index fund is a common build. You then pick the split yourself instead of letting VT's index set it at market weight. Our VTIAX vs VTSAX page shows how that split works with Vanguard funds.
You already own VT and are thinking of adding FXAIX: that raises your US large-cap weight above market weight. Fine if intended; redundant if not.
Taxable account and might switch brokers: VT, as an ETF, moves between brokers in kind. FXAIX can be held outside Fidelity too, but other brokers' fees vary.
Sources & Methodology
- FXAIX summary prospectus, 29 April 2026: fee table, index, purchase rules, returns to 2025.
- VT summary prospectus, 27 February 2026: fee table, index, method, returns to 2025.
- FXAIX Form N-PORT, 31 May 2026 and Vanguard Total World Stock Index Fund Form N-PORT, 31 July 2026: holdings behind the overlap figures.
- Fidelity FXAIX performance page and Vanguard VT profile: returns to 30 September 2026, country mix, holdings count, fund size.
- VT fact sheet, 30 June 2026: top-ten weight.
How the overlap was computed. For each company both funds held we took the smaller of its two weights and summed them, the same method and N-PORT data the Portfolio Overlap Checker uses. The two filings are two months apart, so weights also reflect price moves in between.
This article is for general education and is not investment, tax or legal advice. Past performance does not guarantee future results, and all investing carries the risk of loss. Figures were checked against the sources above on 5 October 2026; confirm current details with Fidelity or Vanguard before acting.
FAQ: FXAIX vs VT
Is FXAIX or VT better?
They answer different questions. FXAIX is the S&P 500 for 0.015%; VT is the whole world stock market for 0.06%. FXAIX returned 15.32% a year over the 10 years to 30 September 2026 against 12.32% for VT, because US large caps led; over the latest year VT was ahead. Pick by how much of your money you want outside the US.
How much do FXAIX and VT overlap?
55.1% by weight, using FXAIX's 31 May 2026 and VT's 31 July 2026 SEC filings. Almost all of FXAIX is inside VT; about 45% of VT is outside FXAIX.
Should I hold both FXAIX and VT?
Only if you want more US large-cap weight than VT's market weight. Holding both raises your US share above VT's 62%. Many investors who want that tilt hold FXAIX with a separate international fund instead.
Does VT include the S&P 500?
Yes. 497 of FXAIX's 501 holdings were also in VT, and they made up 55.1% of VT.
Is VT riskier than FXAIX?
Different risks. VT spreads money over about 10,000 companies and many currencies, and its top ten were about 22% of the fund. FXAIX is all US and its top ten were about 41%. Neither is low-risk; both are 100% stocks.
Can I buy VT at Fidelity?
Yes. VT is an ETF and trades through any brokerage, including Fidelity.
Which is better in a 401(k)?
Whichever your plan offers; you cannot buy outside the menu. If the plan has FXAIX but no world fund, you can hold FXAIX there and add international exposure in an IRA or another account.
Cite This Page
Journalists, educators and bloggers are welcome to cite this comparison. Please link back so readers can reach the underlying filings.
"FXAIX vs VT: The S&P 500 Is 55% of VT, and the Other 45% Is the Real Question." Wealthy Pot, 2026. https://wealthypot.com/fxaix-vs-vt/
Related comparisons: VT vs VOO · VT vs VTSAX · FXAIX vs VTSAX · FXAIX vs VTI · VT vs VXUS · All ETF comparisons
