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. 
No one knows how low the bitcoin will fall, it all depends on the crypto market. But if we look at bitcoin which is the most popular coin in crypto, I think in this year bitcoin will not fall to as low as $ 4000.
I can't understand what is the logic behind this drop to 4k? It's just not gonna happen.