As is often the case, when USDT (or any stablecoin) marketcap sees substantial increases, there is a strong tendency to see BTC & ETH drop by significant percentages. This is because people are selling BTC/ETH, etc for USDT and therefor the marketcap increases substantially. In this case, we're looking at a 5% increase in USDT marketcap and as you can see, BTC is showing a strong downward reversal from it's previous bear rally.