The veteran people on crypto tend to say that you should keep your coins in your wallet, never on exchages. However if there is a strong downwards movement on a coin and you want to sell to buy latter at a cheaper price it may take quite a bit of time and fees to move it. What is the right strategy?
They mean don't use exchange as your primary wallet or don't keep all your money for a long time on exchange, that's it.
If you are a daily trader you might store your coins out there and It's risky but there is no other way, the point is cashout your money immediately from there when you stop doing trading, don't put your money on something where you can't control the private key.