I already invested in Bitcoin when it hitted $15800+,. But I dont keep it holding.
So, do you have Bitcoin in your wallet or not, mate? If you don't hold Bitcoin in your wallets, why you seem to think much about it? It won't get any impact on your assets whether it reaches $20,000 or never.

However, some experts still believe that the bullish season will still continue and the top season may be in the next year, 2021. So, yes there is a chance of Bitcoin to pass its ATH, $20K. If you have some Bitcoin, it is better to not selling all, keep some for the next top bullish season.