Here are 12 of the best mutual funds to invest in as of October 2021: Fund Name and Symbol Fund Performance (Year-to-Date Return) Gross Expense Ratio iShares Russell Small/Mid-Cap Index Fund 15.25% 0.44% T. Rowe Price U.S. Equity Research Fund 16.91% 0.45% Calvert US Large Cap Core Responsible In 15.48% 0.60% T. Rowe Price Large Cap Growth Fund Inve 17.40% 0.71% 9 more rows