In such a highly volatile market, never ran out of cash, I mean, USD cash. When in the market begin a panic, you can find a good chance to earn money. I used to buy BTC with all my planned cash, but it was proven a bad strategy.
I don't know if I could sleep at night knowing I have lots of cash in Mt Gox !
Thats the problem, I dont believe your money are safe there. Wish there were safer options.