derivative?
seems tricky.. and i dont think there's a need for that... we saw a huge lemming-wave like 06/2011 ...rest of the time btc is stable enough for a lot of usages. e.g. transfering money internationally with very low fees... for this you just need 30min of stability...
Unless I'm mistaken, I can't see why people bother to use BTC for international money transfers - you need to go through an agent to convert it to fiat anyway, which ends up being slightly more of a pain than just using a traditional transfer agent.