As much as possible if we were able to buy it at price that seems low from its ATH then buy. Bitcoin is too volatile to predict when will the price go high and up to how much it can reach. What’s good about it is the price is able to go higher whenever there is hype or bull market occurs. The price increase depends on the bype crypto gets from personalities and economy so if we have some to save and plan for long term buying it and waiting for bull market make us gain profit.
Last week bitcoin went down to 45000 usd and IMO it was a reasonable price to buy but irony was we start seeing posts like "are we going in bear market like that of 2018?" Bla Bla. Today after a week bitcoin is standing firmly at 51000 USD. The point is when bitcoin goes away from its ATH, majority start running away from it.