What do you think will be the bottom for Bitcoin, from which it will begin to recover? Another question is whether now is the best time to invest or whether waiting for more dump is advisable.
You can't precisely predict the bottom price of bitcoin since its always uncertain in the first place. No one here is good enough to do that. But you can still invest even if it's not the bottom price, just by doing DCA. After all, your aim is to hold bitcoin for long term investment so even if you don't buy at its bottom, as long as you only sell them at its good and reasonable price, you will still be profitable. Just be patient once you invest as bitcoin may not recover its price easily as it could take a year for it to recover.