Don't Make These 10 Investing Mistakes In '16

Over the last four decades, the 401(k) plan has replaced the pension as the main form of retirement plan. About 31% of workers had so-called defined contribution retirement plans in 2008, up from just 8% in 1980, according to the Social Security Administration. That means many Americans are now managing investments on which their financial well-being depends—and doing it in their spare time.