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...
A lot more than 30mins unless both parties use MtGox as a payment processor. Bank fees are also a rather expensive overhead to get money in and out of exchanges.