What's your main stratergy of investing the crypt-currency??
If you wanna make money by high-frequency trades,you had better choose
some mainstream exchanges,like Bitfinex,Binance,Huobi.Pro.
The mainstream exchanges have good credits,even you assets be hacked and
stolen,they will pay for it.
If you wanna make a long-term invest,you should buy the altcoin and transfer them
to your local wallet.
It's safer to hold your crypt-curr in your local wallet if you keep your private key well.