Most people have a habit of ignoring the small stuff: loose change in a coat pocket, crumpled dollar bills at the bottom of a bag, a few old coins rattling around in a junk drawer. That casual ...

Many people already know that you can turn your loose change into big money when you stumble across rare coins. But did you know that some paper money can also be worth more than its face value?

Pull out your wallet. Before you hand over that bill for coffee, flip it over. Look at the serial number, the seal color, and whether there's a tiny star at the end of the number string. Most of what ...