Leverage created more of a problem in the Swiss Franc situation though. Since a big move in conventional FOREX markets is a couple of percentage POINTS, i.e. fractions of a percent, the leverage allowed is huge, like 30x or so, whereas in bitcoin markets leverage is available but much smaller. I think BTCe only offers 4x leverage, so when BTC drops 30%, you get an effective 120% disparity to cover, but when swiss franc moves 10% with 30x leverage, it's a 300% loss to cover for some. And since national currencies are considered very low volatility, and the swiss franc "as good as gold" there were hundreds of  millions parked in it, with the expectation that the risk profile was low, then shorting it was only considered maybe medium risk... so your medium risk investment, of your many millions, suddenly ends up with a 300% margin call.... that is not a good day.