Not only that, but if Tether's market cap is $20B and their trading volume is $30B to $70B per day, then they completely turn over their entire market cap more

Not only that, but if Tether's market cap is $20B and their trading volume is $30B to $70B per day, then they completely turn over their entire market cap more than 10 times per week. To buy 10x your market cap per week, you also need to sell 10x your market cap per week. It's not a one-way street, there's just as much selling as buying. Traders are well informed. Everyone has known the accusations for years, yet Tether maintains it's $1.00 peg. Let's say for the sake of argument that Tether itself announces that they're only 50% collateralized. Do you think traders would suddenly stop using USDT?