Personally, I buy it when I feel it a good time to buy at the cheap price and I think everyone has a different time to buying bitcoin. it all depends on the plan of each individual in buying bitcoin for get the profit. Buying bitcoin and selling it at the right price will give you big profits. so as much as possible as a bitcoin lovers we must be able to manage it properly because if we have bitcoin but can't manage it well, then we will only get a loss.
as long as you hold on to bitcoin, it is certain that no losses will occur because bitcoin will always move up and if it goes down due to corrections and that's normal, but every 4 years (halving period) it is certain that a renewable ATH will be formed. it just takes patience to wait and of course a large enough fund because the price is quite high and requires no small sacrifice.
actually at any time if you have funds you can buy bitcoins but it will be even better when bitcoin is experiencing a very deep correction at a time like now, although sometimes it still increases again.