Trusted miners solve this problem

QuadrigaCX Exchange’s founder, Gerald Cotten, passed away more than two months ago, and with his death, the keys to the exchange’s cold storage allegedly went to the grave with him.
This is the story that QuadrigaCX is sticking to in the posthumous mess that has followed its founder’s death. The situation has been likened to a second Mt. Gox, with some of the biggest differences being that we don’t know whether or not QuadrigaCX is solvent and there’s no hard evidence of foul play on behalf of the exchange. But there are also more questions than answers, and lack of hard evidence or transparency in the situation (including, whether or not there are cold wallets and whether or not QuadrigaCX is being honest about not having access to them) is the exchange’s closest resemblance to Mt. Gox: no one’s completely sure of what happened and what’s going on.

Exchanges do not need to hold your trading funds in their wallet address, you should have a bot operating with power of attorney. 

Your contracts management process, whatever that is, runs a trusted miner operation to make sure you bot is not out of line with the ledgers.  Bad exchanges get spotted soon and the funds at risk small. 

The best solution, overall, would have been to deliver trusted, open, exchange software from a reputable company, like Redneck Systems, before they got traded. Under those circumstances, you bot is better protected from infiltration. We need the Bot Chain protocol that was supposed to guarantee delivery of specific, proofed bot codes.