I think they are referring to their BTC-settled index futures. Only FTX has them right now - but theirs are settled in USDT, not in BTC: https://contractmarket

I think they are referring to their BTC-settled index futures. Only FTX has them right now - but theirs are settled in USDT, not in BTC: https://contractmarketcap.com/ https://contractmarketcap.com/