As we speak, though they've had problems with downtimes in the past, BitMEX is still the best in terms of reputation and liquidity. Well, probably unless you're from the United States(if I remember correctly US residents aren't allowed to use BitMEX).
Though of course, BitMEX is a huge ass exchange hence it's a huge ass target for hackers so don't unnecessarily leave funds there.
Aside from Binance then Bitmex would be my next preferred exchange yet you can even make some margin trades.Swing or day trade would really be indeed good to this exchange and as we all know on how big the volume or high liquidity it do have.
When it comes to security then its just always been suggested that never ever leave your funds into an exchange no matter how reputable or trustable it is.
If you do then you should at least set all the security like 2fa etc. similar stuffs.