If you've bought bitcoin when it's still cheap and hasn't reached ATH, I think it's time to come out now. Because bitcoin has penetrated New ATH and the current condition is the end of the year and christmas, which can be seen in this annual chart there will be a decline.
Unfortunately, no one knows when the bitcoin price will reach next ATH.
The best thing you can do is sell the bitcoin when the price reaches the peak and wait for a while for another down for the price to buy bitcoin again.
If you sell some parts in many ranges of price, I think that can give you the profit, but that can work if you can place an order sell before the price start rally. But do not place too close because your profit will not be bigger.