The number of 401(k) millionaires hit a new record high

The number of 401(k) plan participants with balances of $1 million or more rose to a record high at the end of June, according to new findings published by Fidelity Investments.

There were about 497,000 so-called 401(k) "millionaires" during the second quarter, the data shows. That marks a 2.5% increase from the previous quarter and is the third-straight quarter of retirement savings growth.

Among those accounts, the average balance hit $1,595,200, up from $1,581,000 at the end of March.