I hear this "unstable" argument a lot. While it's not ready for primetime as a world currency, it's certainly stable enough for 99.99% of all transactions in the world which are less than $10. I'd gladly take Bitcoin for payment of my AirBnB condo's on a bet that the bitcoin will be more more a month from now. If Bitcoin jumped around from $500 to $3000 each week then it would be a problem, but when unstable means that it keeps going up over time then it seems like a ridiculous argument. I think every emerging country should give each citizen $20 worth of bitcoin and get them on the system and make them wait six months before they can access it. Imagine what it would do to a countries economy if the masses woke up 6 months later with value they can trade for goods and a payment system outside of the banks. Bitcoin is going to change the world.