That strategy requires you to have good timing on the market. But the problem is, by doing so, it will make you emotional and you will be prone to make mistakes making you lose some of your money.
If you want the best strategy for ordinary investors like us, "buy the dips". If you have a job you should save 20% of your monthly salary and make that available to buy when Bitcoin's price is falling.
Exactly you will need to time the market perfectly and any strategy that requires you to do it perfectly is simply not going to work for the simple reason that humans are not perfect, and we are bound to make mistakes eventually, no one is able to maintain a level of concentration so high to avoid making mistakes so that strategy is one that is never going to work.