VOO vs VTSAX
VOO is an S&P 500 ETF. VTSAX is a total-market mutual fund. They differ in both what they track and how they're structured — here's how.
Written by Muhammad Hamza
VOO
S&P 500 ETF — large-cap, trades all day
VTSAX
Total market mutual fund — priced once daily
| VOO | VTSAX | |
|---|---|---|
| Issuer | Vanguard | Vanguard |
| Expense ratio | 0.03% | 0.04% |
| Holdings | ~516 | ~3,500 |
| Inception | Sep 7, 2010 | Nov 13, 2000 |
| Dividend frequency | Quarterly | Quarterly |
Sources: each fund's issuer page (Vanguard, State Street/SSGA, Invesco, Charles Schwab, BlackRock/iShares), cross-checked against StockAnalysis.com. Holdings counts are approximate and change daily; expense ratios can change — verify current figures on the issuer's own page before investing.
What each fund tracks
VOO tracks the S&P 500 index, holding roughly 500 large U.S. companies weighted by market capitalization. VTSAX tracks the CRSP US Total Market Index, which includes large-, mid-, small-, and micro-cap U.S. companies — thousands of holdings spanning the entire investable U.S. stock market, not just its largest companies.
| VOO | VTSAX | |
|---|---|---|
| Provider | Vanguard | Vanguard |
| Structure | ETF — trades all day | Mutual fund — priced once daily |
| Tracks | S&P 500 Index | CRSP US Total Market Index |
| Company size range | Large-cap only | Large, mid, small & micro-cap |
| Minimum investment | Price of one share (or less, with fractional shares) | Admiral Shares minimum applies — check Vanguard's current figure |
ETF vs. mutual fund: the structural difference
This is the part that trips people up, since VOO and VTSAX can sound like they're just "different tickers" when the more important distinction is structural. VOO is an ETF: its price updates continuously throughout the trading day as it trades on an exchange, the same way a stock does. VTSAX is a traditional mutual fund: you buy or sell it at a single price, calculated once per day after the market closes, not in real time. That also means VTSAX generally requires going through Vanguard directly or a brokerage that supports it, and — unlike VOO — has historically carried a minimum initial investment.
As of September 28, 2026, VOO charges 0.03% versus VTSAX's 0.04% — a small gap, well under $50/year on most balances long-term investors actually hold, so cost is not the deciding factor here. The deciding factor is structural: VTSAX requires going through Vanguard directly or a brokerage that supports mutual funds, and has historically carried a minimum initial investment VOO doesn't have. Expense ratios and the current minimum change over time — check current figures directly on Vanguard's official VOO and VTSAX pages. A single growth projection can't responsibly represent both funds, since they track different indexes — model each one separately in the VOO calculator.
Which one fits your plan
If you want large-cap-only exposure with intraday trading and no minimum beyond one share's price, VOO fits that. If you want the entire U.S. stock market in one fund and don't mind once-daily pricing and a minimum investment, VTSAX is built for that. If you want total-market breadth but in ETF form instead, see our VOO vs VTI comparison — VTI tracks the same index as VTSAX, just structured as an ETF. This page is educational information, not a recommendation.
Use our VOO calculator to project growth under your own assumptions — the same math applies whether you enter it for VOO, VTSAX, or any other fund.