Charted: S&P 500 Vs. S&P 500 Equal Weight Index By: TalkMarkets October 10, 2024 at 17:56 PM EDT SPY is is the largest ETF tracking the S&P 500 ($585B in AUM), while RSP is the largest ETF tracking the S&P 500 EWI ($64B in AUM). Read More >> Related Stocks: Invesco S&P 500 Equal Weight ETF SPDR S&P 500 ETF Trust