The other major players are mostly Chinese. In China, there's OKCoin, BTCC (previously BTC China), 796, and BitVC, as well as a few minor players. In the rest of the world, there's us, CryptoFacilities, Coinpit, and now Deribit.
We've been in contract with the Deribit team since 2014 - they appear to be a solid tech team and they certainly understand the underlying finance.
