Retirement account balances, which sank at the start of 2025 amid wild market swings , hit record highs in the third quarter, according to the latest data from Fidelity Investments, the nation's largest provider of 401(k) savings plans. The average 401(k) balance jumped 9% from a year ago to $144,400, an all-time high, Fidelity found . The average individual retirement account balance also rose 7% year over year to $137,902. Fidelity's report showed increased interest in Roth 401(k)s and IRAs,