For now, I think the price of BTC is unable to return to 20,000 US dollars, because the sharp drop in BTC prices, which has hit the confidence of investors, it will take a long time to recover. But I think in March 2018 may be close to 20,000 US dollars price.
I also think that BTC won't be able to hit the 20k USD mark in the first quarter of 2018. A lot of investors will wait for more upward movements before they buy bitcoin. But I'm very positive that it will definitely hit that 20k coz when the price is continuously increasing a lot of investors will rush to buy more btc that will make the price even higher.