The reward for mining BTC will halve soon. https://bitcoinblockhalf.com/
This will actually lead to increase of BTC price as supply of BTC decrease and it will become more rare.
Also the total amount of BTC mined ever would be close to 21,000,000 so as quite rare comodity I exepct the price will go up.
Just I am not able to tell when :)
I might be good time to buy now and wait. I think $4,000 investment could bring you 40,000 or even 100,000 and still you risk just these 4,000.