IVV is iShares' flagship S&P 500 index fund and one of the three largest ETFs in the world alongside VOO and SPY. It tracks the same 500 large-cap US companies as every other S&P 500 fund with a 0.03% expense ratio — identical to VOO and far cheaper than SPY's 0.0945%. The practical difference between IVV and VOO is minimal for most investors — both track the same index at the same cost and will produce nearly identical long-term returns. IVV uses an open-end fund structure like VOO, which allows for more efficient dividend reinvestment and better tax management than SPY's unit investment trust structure. For taxable accounts, both IVV and VOO offer better tax efficiency than SPY. The fund has excellent liquidity and tight bid-ask spreads, making it appropriate for both long-term holders and institutional traders executing large blocks. For investors, choosing between IVV, VOO and SPLG comes down primarily to which brokerage account they hold, whether there are any commission advantages and personal preference — the investment outcome across all three will be essentially identical over any meaningful holding period.
