We have had some pretty large moves. The volume of tether just in the past month has been reduced by something like 30%. When people sell off tether batches of it go back and are redeemed for US Dollars shrinking the supply . when US Dollars come in more tether is printed. Everyone knew tether had a lot of money in the bank but people question if they have a 100% ratio in the bank. If they don't, you want to get out early. Before the money goes dry.
There are also better options. Winkle coin has been doing really well. It does everything tether did only better. Also noteworthy there is nearly three times as much tether on the market right now as there was in December of 2017. There are a ton of people waiting on the sidelines with cash in hand.
So I can sell back my USDT to Tether at any time and get dollars from them out of their reserve? I don't believe that's how it works. If it did, any time it dipped below $1 everyone could cash out and make easy money.
At stated value yes. That is not always 1 dollar. Tether pulls shares or redeems every so often just as they print on positive fiat flow