What's Your Biggest Investing Regret?

Our experts know what they're talking about when it comes to saving and investing, but a lot of that knowledge comes from making mistakes along the way. Whether it's selling a stock too early, not taking advantage of excellent buying opportunities, or cashing out of a retirement account, we've done it all and learned valuable lessons from our mistakes. In order to prevent you from making these mistakes, here are three Fools to share their stories.