Only centralised exchanges i.e binance, bittrex,houbi, marcatox, kucoin, hitbtc ,cryptopia, exchanges I feel safe and secure....other exchanges forkdelta, etherdelta is not so safe as above.
im a reguar user of decentralize exchanges but so far i dont experienced any issue regarding on the security of my account but i could say that all exchange are all risky ( whether it is centralized or decentralize ) because money is involved and hackers can potentially attacked your account or the exchange that you are using .
I think the market will not be safe, it is better that you keep the assets you have in the exchange .
if you think that the whole market of crypto are not safe then you shouldnt ever put your money onto crypto . you'd better keep your money on your own hands or find another business that is less risky .