SPY vs VOO

SPYAState Street SPDR S&P 500 ETF

VOOAVanguard S&P 500 ETF

In short

SPY The 1993 original, and still the ticker the market trades through. Same roughly 500 S&P 500 names as its cheaper cousins; the edge here is the crowd around it, not the fee.

VOO Not a standalone ETF but a share class of Vanguard's flagship 500 Index Fund: the same roughly 500 large US companies, 0.03% a year, in a wrapper you can trade all day.

Stated mandate

SPY The fund seeks to track, before expenses, the price and yield performance of the S&P 500 Index.

VOO The fund invests in stocks represented by the S&P 500 Index and seeks to closely track that index's return as a measure of overall U.S. stock performance.

Why people hold it

• SPY One of the most heavily traded funds in the market, and one of the largest. That depth is why desks treat it as the default way to move S&P 500 exposure.
• Its stated job is to track the S&P 500 before expenses, and it hews to that benchmark about as closely as anything in its peer group.
• At 0.09% a year it still undercuts the typical S&P 500 wrapper in its cohort, and it lands in the upper half of that group overall.

• VOO 0.03% a year against a 0.15% median for S&P 500 trackers. On a fund this size, that fee gap is the whole product.
• Holds the index outright, all roughly 500 names, and its tracking record sits among the tightest in the S&P 500 group.investor.vanguard.com
• One of the most actively traded ETFs in the market, which tends to keep the cost of getting in and out small.
• It is the ETF share class of Vanguard's 500 Index Fund, and Vanguard is owned by its own funds, so no outside parent takes a cut.personal1.vanguard.comsec.gov

Worth knowing

• SPY That liquidity has a price: VOO, IVV and SPYM track the same index for a few basis points, and the fee gap compounds over a long hold.
• It is a unit investment trust, the older 1993-vintage wrapper: it holds the index as declared and pays dividends out on a quarterly schedule.
• About 500 stocks, cap-weighted, so the largest companies carry the most weight; equal-weight takes on the same index, like RSP, spread it differently.

• VOO Large US companies only, weighted by size, so the biggest few names carry the most weight and drive much of the move.spglobal.com
• Membership is not purely mechanical: an S&P index committee decides which companies come in and go out.spglobal.com
• SPYM tracks the same index for 0.02%. A rounding error for most, but real if cost is your only tiebreaker.

Full SPY profile⁠

Full VOO profile⁠