Its definitely a great store of value, but saying that it is stable is a bit of a reach right now. Maybe in a few years it may be stable
Someone who would want $100,000 would either buy gold, or silver. Storing value is to make sure that the amount you stored is still that amount in the future, say I stored $1000 in BTC when prices were $1000 per BTC, I'd have just lost 40% in two months, bitcoins are not good for storing value; it is good for making transactions (for use as a currency)