I’d be interested in seeing evidence that USDT “drives” the USD-BTC exchange rate. I do think it’s a good indicator of sentiment about the exchange rate. Typically it’s within $0.02 of its supposed $1.00 value, but today it reached at least $1.08 and is still at $1.06. That means people are willing to pay a 6% premium just to be able to cash out of BTC today.