It does make sense. The price of BTC in USD is roughly the same on every exchange. If some exchanges allow USD and USDT interchangeably, the BTC price can be driven up by trades that are conducted in USDT. The price on Coinbase will adapt to that.
Individuals and bots will take advantage of the price discrepancies between exchanges by purchasing BTC on the cheaper exchange, sending the BTC to the more expensive exchange and selling it. As long as its possible to do this different exchanges normally stay within a few % of each other.
WMX123|5 years ago
qqii|5 years ago