Well Bitfinex is a special case relating to Tether, but I'm sure all exchanges hold some amount of money in some way to support operations. It's just misunderstanding how exchanges work to think a price drop in a thing being traded puts exchanges at risk.
It would only do so if the exchange has a strange unrelated agreement (like to trade 1 USDT for 1 USD), or were holding the money they're using to run their operation in that asset. Except for maybe Bitfinex (because of the special case), no exchanges are doing that with USDT.
It would only do so if the exchange has a strange unrelated agreement (like to trade 1 USDT for 1 USD), or were holding the money they're using to run their operation in that asset. Except for maybe Bitfinex (because of the special case), no exchanges are doing that with USDT.