I think it will increase.
1) because in the 1-2 Month before halving, there will be people speculating and therefor the price will rise
2) because the reward of a mined block will be 12,5 and not 25 BTC anymore. If the demand stays the same its only logical that the price will rise.
These are just my views, nobody can tell what really happens.If someone could say it to 100% he would be rich in a few months.