All electronic coins or digital currency in the cryptocurrency does not have a stable market value. Therefore its price fluctuates in the market resulting to unstable value in a Blockchain market.
Yes price of bitcoin and other crypto currency is not stable. Up and down is happening in crypto market. But it is not a problem in path of bitcoin in future it can be changed to real money. As gold change into real money. That like bitcoin can be changed to real money. Unstability of price is not a big issue in path of bitcoin.