This chart measures Bitcoin Tether price @ Binance / Bitcoin USD fiat price @ Coinbase. If # is above 1.00 means investors value Tethers more than USD fiat. On the other hand #s below 1.00 means Tethers are trading at a discount to USD fiat. 0.98 = 2% discount. Only listed market for Tether/USD fiat is Kraken exchange but there's no real volume going on there, hence this Binance USDT indicator is the best proxy.