Suppose you held funds in a bitcoin exchange. If the exchange is mismanaged and ends folding without giving you the opportunity to withdraw, you'd understandably be pissed. You'd probably seek every possible means and every legal avenue in order to recover your funds, especially if it were for a significant amount.
The question is simple, if you're part of a lawsuit and making a claim, is it better to have been a person holding bitcoin? Or is it better to have been a person who had fiat at the exchange?
In
April 2013 bitcoin-24.com suddenly stop working, no more orders, no more withdrawals, back accounts freezed, a bug in the trading engine, a lot of naivety in the way the business was managed, etc. etc.
Luckily btc24 customers were able to get theirs btc funds back as early as 28th of April, on the other hand some have to wait almost a 10 months to get 72% of their fiat back. And still they're waiting to fetch the other 28% blocked in some fancy poland banking account.
Mind you there are a lot of other cases where the opposite applies. If you bother to search you'll find a lot of horror stories where btc funds simply have disappeared in a breath.
Anyhow, until effective distributed/decentralized exchanges will be up and running, just be extremely cautious.
If you really need to day trade just keep only the amount you need in the exchange account, not a satoshis more. Lastly: due diligence, you've to know with who you're dealing with (the exchange), look for red herrings, weirdness in the management etc. etc.