Third-quarter market volatility, especially in August, hit retirement account balances hard, Fidelity Investment’s analysis of 401(k) and IRA savings shows.

The average 401(k) balance fell to $84,400 at the end of the third quarter from $91,100 in the previous quarter.

A year ago, the average balance was $89,100.

IRA balances fell to $88,700 at the end of September from $96,300 at the end of June, and from $92,100 a year earlier.

Fidelity said in a statement released Friday that it had received a record number of online and telephone requests for help and guidance from its customers in the third quarter.

Between Aug. 23 and Aug. 29, Fidelity fielded some 16 million online inquiries from retirement account investors, and on Monday, Aug. 24 — when the S&P 500 and Dow Jones industrial average closed in a correction — it responded to more than 160,000 phone calls.

The Dow fell by more than 1,500 points in August.

Fidelity said customers asked about how to manage their investments during volatile periods, the possible reasons for recent market drops and the pitfalls of converting to all cash.

Despite their concerns, most investors did not significantly change their asset allocation or the amount of their contributions.

Only 4.9% of 401(k) account holders and 16% of IRA customers made changes to their asset allocation in the third quarter, Fidelity reported.

The average total 401(k) contribution amount dipped slightly in the third quarter, to $2,610 from $2,770 in the second quarter — consistent with $2,670 in the 2014 third quarter.

The average 401(k) contribution rate rose to 8.2% from 8% a year ago.

IRA contributions also remained consistent in the third quarter. IRA account holders added an average of $1,260 to their accounts, compared with the average contribution amount of $1,270 a year ago.

“Recent Fidelity research with the Stanford Center on Longevity found that nearly three out of four pre-retirees cited ‘concern over economic uncertainty’ as a possible reason to continue to work later in life, so we understand that market changes are a big concern for pre-retirees,” Doug Fisher, senior vice president at Fidelity Investments, said in the statement.

“Periods of major market volatility, whether up or down, give investors an opportunity to assess their overall financial wellness, which should include a review of their retirement savings and asset allocation, as well as extend to a more basic assessment of their financial health, including overall family spending and budgeting.”

Fidelity said Roth accounts had become increasingly popular in recent years. At the end of the third quarter, nearly 75,000 IRA account holders had converted to a Roth IRA. Roth IRA conversions by Fidelity customers increased by 36% since last year’s third quarter.

According to the statement, 12% of 401(k) account holders in their late 20s are currently contributing to a Roth 401(k), up from 9% five years ago.

— Related on ThinkAdvisor: