Almost 40% of Millennials Are Making This Horrible Money Mistake

It makes sense for little kids to keep their money in a piggy bank—but a staggering number of adults these days are still basically managing their money the same way.

A new survey from Bankrate.com finds that 23% of American adults think cash, in the form of savings accounts or CDs, is the best place to keep a long-term investment.

It’s not.