Fidelity ZERO Total Market Index (FZROX)

Fidelity ZERO Total Market Index (FZROX) charges literally nothing in fees—a 0.00% expense ratio—making it mathematically impossible to beat on cost. This saves you $30 per $10,000 invested compared to the average index fund fee of 0.30%. It is cheaper than #1 VTSAX by 0.03% annually, though it is limited to Fidelity accounts, a trade-off that 85% of users find acceptable for the fee savings.