Investors who’ve had 401(k) accounts at Fidelity for a decade saw their average balance increase sixfold to almost $300,000 since the market bottomed after the global financial crisis, the company said.

Workers saving for retirement saw their 401(k) balances crater in the 2008-to-2009 market meltdown. Ten years ago, in the first quarter of 2009, investors had an average account balance of $52,600, according to a report Thursday by the Boston-based firm. In March of that year, the S&P 500 index hit a low. It has more than quadrupled in value since.

Fidelity examined the accounts of 1.64 million individuals who invested in the same 401(k) plan over the past 10 years and found that the average balance reached $297,700 as of March 31. Baby boomers -- many of whom have already reached retirement age -- had saved an average of $357,200 as of the first quarter, while accounts of millennial savers averaged $129,800. Gen X investors saw average accounts rise to $268,900 from $37,000.

Across a wider universe of 30 million retirement accounts tracked by Fidelity, including those of employees who’ve only been in the workforce a short time, the average 401(k) totaled $103,700 in the first quarter.

The number of people with more than $1 million in their account also increased last quarter to 180,000, from 133,800 at the end of the fourth quarter, according to Fidelity, which is one of the biggest administrators of employer-sponsored 401(k) plans in the U.S.

This article was provided by Bloomberg News.