From $17,000 to $500
My Dumbest Investment

By sheer coincidence, I received a spam e-mail with a stock tip just one day after I signed up for a legitimate stock recommendation service. I didn't pay as much attention as I should have and assumed the spam e-mail was legitimate. I sunk more than $17,000 into a penny stock at an average cost of $0.166 per share. It's at less than half a penny per share as I write this, effectively turning my fat nest egg at age 21 into a paltry $500. But you learn from these things, I guess. I've been trying to learn more about investing ever since, and I hope to eventually make my money back and more! - Dave Selinger, Oklahoma City, Okla.

The Fool Responds: You're smart to keep at it, though this was a painful lesson. Always avoid penny stocks - those trading for less than $5 per share - and do some digging into any company you're considering. If you don't see promising signs, such as growing revenues and earnings, think twice before investing.

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