The cryptocurrency market is unpredictable, so it is very difficult to say when Bitcoin will return to $ 20000. But I'm sure this price is really achievable and at the end of this year, Bitcoin will get this price.
Absolutely the Bitcoin has the potential and strength to cross 20k dollar and we are waiting for that time and expecting to cross by the end of this year. We know that in the start of 2017 the market price was low and suddenly we saw a better value by the end of year.
Similarly this year the value is going low and by the end of the year it will show a better value again as we know that the demand is increasing these days.