2025年，共同基金的IRA投资者将资产集中在低成本共同基金中（pdf）

Individual retirement accounts (IRAs) have helped millions of US households save for retirement and representthe largest share of assets in the US retirement market. Of the $18.7 trillion in IRA assets at year-end 2025, 40%was held in mutual funds, with IRA mutual fund investors primarily invested in equity funds. Like other mutual fund investors, IRA mutual fund investors have benefited from the downward trend in fundexpense ratios. Percent Percentage of IRA equity mutual fund assets, year-end 2025 Average Expense Ratios for IRA Mutual Fund Investors Are More Closely Aligned WithIndustrywide Averages Than 401(k) Mutual Fund Averages Asset-weighted average mutual fund expense ratio; percent, 2025 Deeper Dive: A Comparison With 401(k) Mutual Fund Investors The data show that401(k) investors, on average, incur lower expense ratiosin their mutual fund holdingsthan IRA mutual fund investors. One reason for this is economies of scale—many employer plans aggregatethe savings of hundreds or thousands of workers and often carry large average account balances, which aremore cost-effective to service. In addition, an employer that sponsors a 401(k) plan may defray some of thecosts of running the plan, enabling the sponsor to select lower-cost funds (or fund share classes) for the plan. Another difference is that IRA investors often pay for theassistance of a financial professional wheninvestingand sometimes cover the cost of this service by investing in a fund (or fund share class) that has a12b-1 fee. This fee, which the fund collects and passes to the financial professional assisting the IRA investor,is included in the fund’s expense ratio. 401(k) plan participants have generally had more limited access toprofessional financial advice, so 401(k) plans commonly select funds (or fund share classes) that provide nocompensation for financial professionals—which partly explains their somewhat lower expense ratios. Take acloser look at the data. For more information about IRAs, visit ourIRA Resource Hub.