VOO vs SPY: Does It Matter Which One You Choose?
VOO and SPY both track the S&P 500. Here's what's actually different, what doesn't matter much, and how to think about the decision.
In this article
This comes up constantly for people just getting started: should you buy VOO or SPY? Here's the short version, the practical differences that actually exist, and — just as importantly — what doesn't matter nearly as much as it might seem.
The short answer
VOO and SPY both aim to track the S&P 500 index, so their underlying holdings — roughly 500 large U.S. companies — are very similar. For most long-term investors, this is a smaller decision than it feels like. For the full structural breakdown of each fund, see our dedicated VOO vs SPY comparison page. This article focuses on how to actually decide, rather than repeating every fact about each fund.
What's actually different
- Fund structure. VOO is an open-end fund managed by Vanguard. SPY is structured as a unit investment trust (UIT), one of the oldest ETF structures, managed by State Street. This affects some technical details, like how each fund can handle dividends internally.
- Trading volume. SPY has historically been one of the most actively traded ETFs in the world, with a deep options market — part of why it's popular with active traders. VOO is also highly liquid, but generally sees less trading volume and a smaller options market.
- Share price and expense ratio. Both can change over time and either fund may currently be cheaper — check current figures directly on each provider's official page before comparing.
What doesn't matter much
For a long-term, buy-and-hold investor — someone not actively trading options or relying on intraday liquidity — the ticker choice itself has a limited effect on the actual investing outcome, since both funds are trying to do the same job: match the S&P 500. Neither fund is designed to outperform the other, so choosing one over the other isn't a bet on relative performance the way choosing between two individual stocks would be.
What might actually matter for you
- What your brokerage offers. Some retirement or workplace accounts may only offer one of the two, which can settle the decision for you.
- Fractional shares. If your broker supports fractional-share investing, share price becomes less relevant either way; if it doesn't, a lower share price means your fixed contribution buys more whole shares.
- Whether you trade actively. If you plan to trade in and out frequently (generally not recommended for long-term investors), SPY's deeper options market and trading volume may matter more to you than it would to a buy-and-hold investor.
Why the projection math is basically the same
Because VOO and SPY track the same index, a growth projection for one is a reasonable stand-in for the other, with the caveat that their expense ratios may differ slightly — check current figures before assuming they're identical. That means you can use our VOO calculator to explore a plan whether you end up choosing VOO, SPY, or another S&P 500 fund.
Project a plan for either fund
Since VOO and SPY track the same index, this calculator is a reasonable way to explore a plan for either one.
Try the VOO CalculatorFrequently Asked Questions
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This is an educational calculator, not financial advice.
Results shown are estimated future values based on the return assumption you enter — they are not predictions and VOO is not guaranteed to achieve any particular return. Past performance of the S&P 500 or any fund does not guarantee future results. Consider speaking with a licensed financial professional before making investment decisions.