A study from earlier this year found that 401k investors sometimes follow what I call a “naïve” investing strategy. These workers evenly divide their 401k money among their mutual fund choices. Thus if a plan has 5 investment choices, a worker invests 1/5th in each fund; if a plan has 7 choices, the worker invests 1/7th in each fund. The problem is that the people who choose your plan investment options aren’t making plan choices—in any way at all—along this train of thought. The result? A potential train wreck for your retirement savings.