1 in 5 Millennials Are Making a Huge Investing Mistake. Here’s How They Can Fix It

It's no secret the financial crisis was a traumatic event for many millennials. Yet new research suggests that those scars still linger even now — and, for a significant minority, may be imperiling their retirement security.

The oldest millennials, born around 1980, were in their mid-20s when the 2008 financial crisis hit.