Jitters about retirement savings have mushroomed as the Wall Street crisis has grown ever more ominous. During the first week of the meltdown last month, $411 million in 401(k) money was moved into fixed-income funds, including stable value, bonds and money market funds, according to Hewitt Associates.

If you're five years or less from retirement, there's no shame in seeking refuge in safe investments to calm a knotted stomach. "This is the most conservative I've been in almost 25 years," says Sheryl Garrett, a financial planner in Kansas City, Mo. "It's all about preservation."

Garrett says skittish investors might consider moving about 20 percent of a retirement account from stocks to stable value or fixed-income accounts that invest in government bonds or Treasuries. "You won't hit home runs," she says, but adds, "You'll still get a modest positive rate of return."

But financial planner Amy Noel of Boulder, Colo., says investors retiring even in two years likely will live another 20 or 30 years and will need higher returns to keep up with inflation. She recommends against a big shift from stocks to fixed-income assets unless you'll need the money in two years to buy a house or pay college tuition, for example.

One way to buy low and sell high is to enroll in plans that automatically rebalance portfolios every quarter to maintain a target mix of assets regardless of market conditions, says financial planner Barry Glassman of McLean, Va. That could mean 70 percent of assets in stocks for younger investors and 40 percent for retirees.