We can never tell because the market is too volatile anything can happen it might go up or go down. The prices may vary depending on how many dump or pump bitcoins. For as long the investors believes in bitcoin definitely it will not decrease in value and it will continue to rise.
There is not even 0.001% chance of reduction of prices of bitcoins in future because the price of Bitcoin is going high rapidly and millions of people are investing in bitcoins just because they know that it will never happened to Bitcoin that it will reduce it price Bitcoin will just increase its price.