A website called CoolSerialNumbers.com is currently collecting currency with “fancy” serial numbers. If you have a bill with one of these fancy serial numbers on it, you could stand to make hundreds or even thousands of dollars by selling the site your bill. Here’s what to look for:

7 repeating digits in a row on $1 Federal Reserve notes (e.g., 09999999, 18888888, 19999999, etc.)

7 of a kind on $1 Federal Reserve notes (e.g., 00010000, 00090000, 90999999, etc.)

Super radars on $1 Federal Reserve Notes (e,g,, 01111110, 10000001, 80000008, etc.)

Super repeaters on $1 Federal Reserve notes (e.g., 67676767)

Double quads on $1 Federal Reserve notes (e.g., 11110000, 44440000, 88880000, etc.)

And that’s not all! Check out the site’s Want List to see what other serial numbers they’re on the hunt for.

Isn’t it incredible how something as seemingly inconsequential as a crumpled $1 bill could actually make you a ton of cash? Check your wallets, people! Today might just be your lucky day.