Fidelity 500 Index Fund (FXAIX)Source: Shutterstock Expenses: 0.015%, or $1.50 for every $10,000 investedFormerly Fidelity Spartan 500 Index Investor Shares, the Fidelity 500 Index Fund (MUTF The Fund seeks a total return which corresponds to that of the S&P 500 Index. The Fund invests at least 80% of its assets in common stocks included in the Index. The Fund may lend securities to earn income and uses statistical sampling techniques in stock selection. About Fidelity 500 Index Fund. Fidelity 500 Index Fund seeks investment results that correspond to the total return performance of common stocks publicly traded in the United States by investing in common stocks included in the S&P 500 Index, which broadly represents the performance of common stocks publicly traded in the United States.