VOO vs. SPY: Is There Actually a Difference?

Key Points The Vanguard S&P 500 ETF (VOO) and the State Street SPDR S&P 500 ETF (SPY) are two of the largest funds in the world. VOO is cheaper and generally preferred by retail buy-and-hold investors. Big institutions tend to like SPY's strong liquidity and tradeability. 10 stocks we like better than Vanguard S&P 500 ETF › If you're trying to choose between the Vanguard S&P 500 ETF (NYSEMKT: VOO) and the State Street SPDR S&P 500 ETF (NYSEMKT: SPY) , it might seem they're essentially interchangeable. They're both huge and track the same index. At a high level, that's probably true. But if you want to dive deep and get picky, a few factors set them apart. Missed AI’s "Act 1"? Act 2 Could Be 15x Bigger.