I am a trader or at least that is how i see myself. I trade on binance, okex, idex, mercatox, bittrex, houbi and some other exchange. Lately i notice a lot of new crypto exchange popping here and there. And as much as i know and safe guard my password and secure my account with 2fa, I am still curious of the factors other traders consider when they are signing up on a new exchange. Would love to know some of your key factors so i might look into those too.
First and foremost, look at the history of the exchange. If they exists for a number of years now, it may further strengthen their position as a trusted/top exchange in the internet. Another thing to look for is their history of security. Although all exchanges are prone to scamming, look for exchanges that has tight-security. Lastly, exchanges vary on the price of their trades. This may be a key factor on determining which type of exchange website one should use.
Good exchanges also has a good reputation based from the trader or user community this includes no scam accusations, no hacking incidents, no malicious activities like funds disappearing, best security practices applied and most of all a good exchange has a huge volume which may satisfy a buyer or a seller to make transactions faster and easier and more convenient.
Even exchanges with a good reputation have been "hacked: and stolen money from their customers. No matter how reputable an exchange is the coins aren't truly yours unless you hold the private keys yourself.
No exchange is safe from hacking due to their nature existing in the internet. I would take your advise to have your private keys stored in a physical hardware for maximum security. But some reputable exchanges have insurance that can answer assuming that their system has been hacked and stolen.