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. 
Theoretically, bitcoin could fall in price and below $ 4,000. It has a very high volatility and therefore it is quite possible. However, I do not think that this will happen soon. Bitcoin has long passed the price bottom after its fall and is unlikely to be further reduced if the situation again does not change dramatically.