Basic fibs.
The whole move in 2017 was a full fib extension, plus 157%, there or thereabouts.
Using the information to hand, if there is a similar move this bull market, the price could reach $30+.
Who knows if it will happen or not as there is a lot going on fundamentally, but there is a hell of a lot more liquidity today, compared to 2017.
I don't own any cryptocurrencies and this is not financial advice. It's purely fun to look at the charts and give my unprofessional take.