It is quite difficult to answer this question. If Bitcoin is having a stable price, then it will be popular with merchants and bankers. But at the same time, its attractiveness among the traders and the investors will take a hit.
Yes, investors and traders bitcoin will not be interesting, because they use it only because of a good price increase.
I think opposite, if bitcoin price stable. So will many long-term investors who invest money in bitcoin in a very large amount. And bitcoin could potentially be an international currency.