Currently BTC prices have been hovering at 6000, and if the BTC prices fell to $5000, $4000 should be not far off, the market is confirmed in the bear market, want to rise to $20000, you may need a couple of years. 
as you can see, $4000 didnt happen, the lowest price of bitcoin as of now is above $5000, and after that, its price is starting to increase, and there are some prediction that its price might reach $8000-$10000.