They run perpetual contracts on the top 5 crypto assets and have leveraged tokens that are like pseudo ETFs which take positions in the perpetual contracts to track the value of 1x short (HEDGE), 3x short /long(BEAR/BULL), 10x short/long (DOOM/MOON). There is also a fixed maturity "MOVE" contract that is trading the volatility of the contract, i.e., betting on how many points in a day a given index will move.
Margining on FTX is done relative to USD, which is a new model in the industry which usually just allows one type of collateral in futures trading. This approach is like a hybrid of BitFinex's margin trading and the existing dominant futures exchanges.
FTX also offers interesting index contracts like SHIT which is the shittiest shitcoins, ALT which is the "blue chip" shitcoins, and "mid" which is the mid-tier shitcoins.
And of course, they also offer standard fixed maturity contracts for next two quarters (currently December and March). This makes them a firm competitor for OKex and BitMEX as they offer multiple forms of deposit, a unique margining system, an affiliate program that pays out 30%, and innovative contracts and products with the leveraged token.