You need to keep a limited amount of your funds on exchanges and the rest in cold storage devices such as Trezor, that would be my advice, then you can move coins to and from exchanges as and when required. In order to trade, I also have "lost" a decent sum of Etheruem as I cannot seem to access my etheruem wallet due to loss of a private key, although I can see the funds through my trezor!!!
RE: Bitcoins, solution for huge problem?