The S&P 500 has been around for decades, but when you're buying it, are you really choosing the right ETF? There are 4 ETFs that track the S&P 500 index—VOO, SPYM, SPY, and IVV—but each has its own unique features. Here’s a breakdown of their data: VOO Assets under management: ~$1T+ Expense ratio: 0.03% A core product from Vanguard, it’s a popular choice for long-term investors thanks to its low cost and massive scale. IVV Assets under management: ~$820B Expense ratio: 0.03% A flagship ETF from BlackRock, it’s also favored by institutional investors for its low fees and scale advantage. SPY Assets under management: ~$750B Expense ratio: 0.0945% Launched in 1993, it’s the OG S&P 500 ETF. Known for its high trading activity and a well-developed options market. SPYM Assets under management: ~$140B Expense ratio: 0.02% A low-cost product from SPDR, pushing the cost competition for S&P 500 ETFs to an even lower level. If we simplify it For long-term holding: VOO / IVV For the lowest expense ratio: SPYM For trading depth: SPY In the past, investing in the S&P 500 was all about the index itself. But as ETF competition heats up, factors like expense ratios, scale, liquidity, and product design are becoming increasingly important when making a choice. Same S&P 500, different ETFs—each catering to different investment needs.