Option 1 - means for investment.
In this case, the stability is very damaging, because there is no possibility to earn it. The cost should fluctuate within 10% (BTC - 10-15K)
Option 2 - means of payment.
For BTC as a means of payment, stability is needed and, given the considerable commission in the transfer, this currency will be used for the purchase of goods more than 1K. (BTC - 6K)