Finding the perfect moment to buy bitcoin is literally impossible. Whatever the price the trader has not acquired an asset with a high probability it will fall before moving into a phase of long-term growth. Therefore, some investors use the "averaging" strategy.

My strategy works like that: split the capital into several parts and buys bitcoin with them over time. Thus, if the price of the asset falls, you can use this as an opportunity and buy more coins. In this case, the average purchase price of BTC will decrease.
Each user can determine for himself how much he will divide the capital. The more of them — the more average the price will be. The best option is to invest $25 in BTC every day. Do not waste time on other assets, do not spend money on currencies that are less known and that have been on the market for as long as bitcoin. Simply buy the most famous digital currency on a daily basis.