The last ATH was $64k and the current last price was $19k. There seems to be a -$45k reduction. Of course, the reduction is extraordinary, and the bitcoin crash for 1 year has made many people start to clean up and start buying bitcoin for the long term.

The bitcoin price of $19k is a low price, there's no harm in buying at the current price, but another crash is possible. Be prepared with spare money that you still have, of course, it will be very helpful to buy even cheaper. Buy and hold for the long term, Bitcoin won't disappoint, ATH $64k might be a very low price in the future. Do your research, manage money well, and find out your best strategy.