Why do you consider Okex noname? As for Deribit, I can still agree. In principle, Okex is already quite popular and has earned a reputation and a name. Confirmation to that - https://www.trustpilot.com/review/www.okex.com. Bitmex, no doubt, is already well known - https://revain.org/exchanges/bitmex. But you cannt use only one exchange. We need a well-known diversification. Therefore, can add another one exchange to use - https://revain.org/exchanges/okex. Of course, everything is individual and the list goes on.