How often do you really look at the dollar bills that you get as change? You might glance down and see George Washington staring back up at you, but it turns out, you should be taking a much closer look than you’ve been doing. That’s because the serial number on the bills could make them worth way more than one dollar.

The_Coin_Guy on TikTok recently shared a video pointing out one thing in particular to be on the lookout for. In the clip, he shows a dollar bill that has a serial number with all 8s, something that is called a solid serial number. He explains that they are “extremely collectible.” To prove it, he showed how much that bill sold for – $7,500.