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 far as I am concerned, we can say that the price of bitcoin will drop to 4000 dollars and do not. We did not know if this dropping price reach 4000 dollars. Personally, Its really hard to predict whether it will happen or not, as you can see the price is suddenly ups and down. Depends on the day, that is why I always check the market price so I can think a solution if this 4000 dollars down fall happened.