Pull any bill out of your wallet. See the dark green numbers on the top-left and top-right corners? Those are serial numbers, and some are more rare than others. If you happen to have paper money with ...

Most people glance at a $20 bill just long enough to confirm it's real before handing it over or tossing it in a deposit envelope. That's completely understandable. What most people don't realize is ...

Most people who receive a $2 bill tuck it away in a drawer, assuming it's too unusual to spend and too ordinary to be worth ...