The way this is managed in the stock/futures markets is by hedging with options (think insurance policy).
So if there were such a thing, for every $1000 bitcoin, I would pay say $10 for a Put Option. Then if bitcoin crashed to $800, the Put Option would pay out $200 or so, covering my losses. Sounds like an insurance policy, right!
If bitcoin kept climbing, the $10 Put Option would be worthless, and I just look at like I paid an insurance premium.
Unfortunately, I don't see an analog to bitcoin where this can be done. Gold has been suggested, but the correlation is not secure enough. If Gold were correlated, then you could just BUY a Call Option on Gold for $10 (as an example). Then if bitcoin crashed, and gold went up, your Call Option would pay you.
For a market maker to step in an create such an option, they would need a place to lay off their risk.
But it will come soon. Until then, as always, stay vigilant.
: )
cj
mpex.co offers trading of bitcoin options. However, those markets are highly illiquid..