I am really happy to see bitcoin rising again. This happened in 2017 and I believe it will not stop at $20k as in the case of 2017. The price will bypass $20k but will decline again arouny $25k. If you are expecting it to decline now the you will make a mistake. If you want to invest, invest now.
The current market phase has progressing firmly and bitcoin's value precisely shown accomodating price that tend to satisfied people's choice. And I think it able to grow up bountifully and touch $20k this 2019 with our positive mindset.
At least with last ATH, people will know when to join or when to take profit from this condition. Because even make highest target for bitcoin price is actually good to do but know when to stop is better.