The 100 dollar bill is the most popular product from the Federal Reserve. Eighty percent of all U.S. cash is in the form of 100 dollar bills, but you rarely see them. About twenty years ago, the Fed counted up all the hundreds it knew about — money in bank vaults and cash registers — and it found it had no idea where most of the hundred dollar bills had gone. And so they went on a mission to find them. Today on the show, where in the world are all the 100 dollar bills? What is Benjamin Franklin being used for? And if we don’t know where they all are, should the U.S. keep making them?