It is slowly going down right now, and it is a good sign that the pump that has happened is obviously because of hype or the possibility of it being manipulated. I dont expect bitcoincash to ever dethrone bitcoin and dont just look at the price, just look at what everyone uses for transactions, it is bitcoin and not bcc. Those who use bitcoincash oftenly use it for speculation so even if bitcoin cash would go up way above bitcoin price, I wont say that it has dethroned bitcoin unless most of bitcoin users have already switched into bitcoincash.