Looks like an old Lend Lease era American bearer bond. The Allies sent hundreds of these overseas during WWII, most valued in the tens to hundreds of millions of dollars to rebuild Europe, many of them never arrived and are presumed to have been stolen by servicemen who brought them back to the States. If you bring that to to the federal reserve they legally have to pay you 100 million dollars. I'm obviously joking, that's likely something a child bought for ten cents from the back of a comic book back in the day.