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.
VOO
S&P 500 ETF — large-cap, trades all day
VTSAX
Total market mutual fund — priced once daily
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.
Expense ratios and the current minimum investment for VTSAX change over time — check current figures directly on Vanguard's official VOO and VTSAX pages rather than relying on a fixed number here.
An illustrative growth example
Because VOO and VTSAX track different indexes with different breadth, a single growth projection can't responsibly represent both. The chart below illustrates the compounding mechanism only — $500 invested every month for 20 years at an assumed 7% annual return — not a claim that either fund would actually produce this outcome.
At this hypothetical rate, the 20-year total works out to $260,463, of which $120,000 came from contributions.
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 VOO's growth under your own assumptions, or the investment calculator for a general projection that works for VTSAX or any other fund.