The average 401(k) is down 14 percent this year, according to Hewitt Associates, which released a study that found workers are increasingly cautious about investing in corporate retirement funds.

Hewitt found 4 percent of workers had stopped contributing to their plans in response to Wall Street declines. Stock holdings now account for 53.8 percent of assets, down more than 14 percentage points from a year ago. At their peak in 2008, almost three-quarters of assets were in equities. More employees are also taking cash from their 401(k), despite penalties and additional taxes. Overall, 6 percent of employees pulled money out, up from 5.4 percent a year ago. So-called hardship withdrawals are up 16 percent.