In a good sign for retirement savers, the average 401(k) account balance reached a record high of $106,500 at the end of the third quarter.

That's just one of the upbeat findings from Fidelity Investments' latest quarterly analysis of retirement saving trends for its 30 million holders of 401(k) or IRA accounts.

The record balance for workers with 401(k) plans marks a nearly 7 percent increase from a year earlier and tops the prior record balance of $104,300 from last year's final quarter. Account balances at the end of September were nearly double the average balance of $56,900 401(k) back in the third quarter of 2008 during the financial crisis, Fidelity said.

The average IRA balance also notched a record, climbing to $111,000, more than double the $52,000 balance from the third quarter of 2008.

Stocks, however, have turned volatile in the final quarter of 2018. In October, the benchmark U.S. stock index, the Standard & Poor's 500, briefly fell into correction territory, defined as a 10-percent drop from a prior high. Heading into Monday's trading session, the S&P 500 was down 7.1 percent from its record.

One of the positives of the financial crisis was that it motivated investors to educate themselves about the steps they should take to "protect and grow" their retirement savings, said Kevin Barry, president of workplace investing at Fidelity.

"We've seen an increasing amount of positive savings behavior over the last 10 years, which helped put many people back on track for their retirement savings goals," he said.

Savers have also benefited from new 401(k) plan benefits, such as automatic enrollment as well as employers placing workers that don't select specific types of investments into so-called default options like target-date funds. These funds have skyrocketed in popularity. They have a more aggressive mix of assets — including a bigger helping of stocks — when people are younger but they become more conservative as workers near retirement.

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Other highlights from Fidelity's latest retirement savings analysis:

Record number of 401(k), IRA millionaires

The number of Fidelity 401(k) holders with balances of more than $1 million increased to 187,400 at the end of the third quarter, up 41 percent from a year earlier and topping last quarter's prior record of 168,000. The number of IRA millionaires rose to a record 170,400, 25 percent more than a year earlier.

More Money:401(k) millionaires at Fidelity jump 41 percent in third quarter to record 187,400

Contribution levels from women notch record

Female investors contributed a record 8.5 percent of their pay, on average, to their 401(k)s in the quarter ended in September. What's more, 32 percent of women with 401(k)s increased the amount of money they set aside in their accounts over the past year, up from 14 percent in the 12-month period ended in the the third quarter of 2008.

Target-date funds gain bigger following

The popularity of target-date funds, or funds that take more risks when savers are younger and fewer when workers near retirement, continued to grow. For the first time, more than half (50.4 percent) of 401(k) savers had all of their retirement savings in target-date funds.

Just over 30 percent of all 401(k) assets were invested in target-date funds at the end of the third quarter, up from 9.8 percent 10 years earlier. And a little more than half (51 percent) of all new investments in 401(k)s was deposited into these funds.

Balances of consistent millennial savers on rise

The average balance for members of the millennial generation who have been invested in their 401(k) plans for five straight years topped $80,000, up from $20,600 five years earlier.

Nest eggs of long-term 401(k) savers swell

The average balance for Fidelity 401(k) investors who have stayed invested in their 401(k) accounts for five consecutive years reached $221,200 at the end of the third quarter, up from an average of $103,700 five years ago.

And the average account balance for investors that have been saving continuously in their 401(k) plans for 10 years reached $305,400. That balance was nearly five times the $65,700 amount for this group 10 years ago.

Workers who have been saving in their 401(k) since the third quarter of 2003, or for fifteen straight years, have seen their average balance increase to $400,300, up from $47,800 back in 2003.

"These groups of long-term savers are great examples of how a consistent approach to retirement savings can lead to significant financial gains over the long run," Fidelity's Barry said.

