There are theories out there that 401K investing is what drove this market crazy in the first place. Not sure I buy that but in any case, if you're 25 there is no reason to start moving your retirement money to money markets. The market will rebound, it always does. It may not be this year, heck it may not be five years but if you start getting conservative you will lose out in the long run. 401Ks are instruments you tune up annually - not when the market tanks. Unless you have that money earmarked for something in the next two - three years you should leave it where it is. Of course, some people can't handle the swings (which is fine) and so then cash or money market is the way to go but realize that you will lose out on gains in the long run. (and do some research on the web before listening to me. I'm just a schmuck that worked at mutual fund company for three months and read the Wall St Journal Guide to Investing during down time).