Some people says that the wrost thing to do is leave your bitcoins in some exchange.
I have 200 usd of btcs in Payeer, it is a online wallet but it also has a exchange.
Do you recommend to me to move this bitcoin to a wallet like Electrum?
Well, there isn't a way that one can trade on an exchange without leaving certain amount of btc there for impromptu and opportunistic buying. I don't think that $200 worth the OP mentioned is a big deal. It isn't much of a risk if you asked me. It should be a buffer for OP's convenience. What I do not buy into is people leaving several thousands of dollar worth in an exchange.