iShares Core S&P 500 ETF (IVV)

IVV offers ultra-low-cost index tracking with a 0.03% expense ratio, making it cheaper than the average S&P 500 ETF. Managed by BlackRock, it holds $510B in AUM and is preferred by institutional investors for near-perfect tracking accuracy. With annual tracking error below 0.02% and daily volume of 5M+ shares, IVV rivals #2 for cost efficiency among core portfolio holdings.