Bittrex is number one exchange for trading and holding your coins in their wallets as i have not heard any news either of any phishing or hacking attack and their security features are very strong.
I agree with you . Bittrex is the safest exchange and all my properties are on this exchange. I can easily profit from trading and everything in Bittrex is very easy for me. I hope in the future Bittrex will list more new altcoin