have another question:
What if an exchange where you have majority of your funds is hacked?
So let's say half of all investements are gone.
What do you do? Will you pay it from you own money?
What if you do not have enough money to cover losses?
Sorry for super late reply: - but this can be avoided or atleast mostly mitigated by using special strategy where you never keep more than 50% funds on exchanges plus it has to be spread out evenly - in such case you only loose small part of funds.
Also you don't pick exchanges that are not controlled properly or licensed etc.. or are not trustworthy - most bigger exchanges bitstamp,kraken, gdax, etc are capable to undo the damage if it happens for example.
So minimize exposure, don't keep big sums on one exchange, pick good exchanges, make sure you're accounts are safe, make sure investors are aware of the risks and they accept them.
for example: You say to clients that max loss could be 25%. And either they accept this or they don't participate.
Cheers