Common advice is to keep your currencies safe by placing them into storage. I feel this is risky considering coins have dumped to all time lows within short periods of time. The alternative would be to keep them on an exchange and set stop losses, however, this is also risky as exchanges or your account can be compromised. How do you manage these risks?
If you don't have any intention to sell your coins at some time, no need to put them on exchange. And even let's say you put them on the exchange, why set up a stop-loss if your purpose is just to hold. Your coins will still have the same quantity, bull or bear. The values of it are the only ones that will change).
It's not wrong to put your coins on the exchange so you won't be late when you want to sell it but to lessen the risks, choose only those reputable and big exchanges and you should know what's the risks. But only do this if you intend to sell your coins and will not wait for long.
But to lessen your worries that the exchange might turn into scam no matter how big it is (although it won't likely happen now), then just transfer your coins when you want to sell it. Transferring your coins from your own controlled storage to exchange or trading sites will not consume much time.