Who's it that says bitcoin has a specific period of purchasing it bitcoin? You should change that awkward thought and get your coins at when you can for bitcoin would always hold the best for you in the nearest future.
Bitcoin is not just about price but Bitcoin value even though everyone who chooses to hold for the long term saves the goal of profit from returns when the price rises high.
For investors who choose to use the DCA method, which is carried out regularly every time and aims for the long term, perhaps they don't care too much about the price because if you calculate the amount, in my opinion they are in a profitable position.
For me personally, price doesn't really matter when it comes to getting Bitcoin to hold long term.