From $17,000 to $500

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.

Do you have an embarrassing

lesson learned the hard way?

Boil it down to 100 words

(or less) and send it to The

Motley Fool c/o My Dumbest

Investment. Got one that worked?

Submit to My Smartest Investment. If we

print yours, you'll win a Fool's cap!