Not panicking in times of market turmoil tends to pay off. Fidelity Investments found that pre-retirees who sold all their equities in late 2008 or early 2009, near or at the market bottom, and never rebalanced back into equities saw their 401(k) balances grow nearly 26 percent as of 2013's first quarter, to an average of $101,000. That doesn't sound so bad, until you look at how the pre-retirees who didn't sell out of equities did. Their average balance nearly doubled, to $255,000.
That's the average performance for September going back to 1927, according to data compiled by Bloomberg You might, however, want to go in every year and increase the percentage of salary you defer into your 401(k). Doing that when a raise is about to go into effect is a good idea, so you won't miss the money.