Let's say you think Bitcoin is going to crash (or you're a trader and just think it's going to go down). Obviously you want to sell your bitcoin, but also postu

Let's say you think Bitcoin is going to crash (or you're a trader and just think it's going to go down). Obviously you want to sell your bitcoin, but also postulate that you don't have a connection to a real bank (KYC and all that), so you can't actually turn your Bitcoins into dollars. So you sell your Bitcoins for Tethers. Then Bitcoin goes down, and eventually you buy them back using Tethers.