The proactive way is that you need to accurately predict the bottom of the stock market in order to level the cost at one time.
The passive way is not to predict the bottom of the stock market, but to subscribe for funds regularly by means of fixed investment. If the market goes down, you get the effect of spreading the cost. If the market goes up and rises above your cost, you get the benefit.
Theoretically speaking, it is almost impossible to dilute the cost at one time, so I suggest you adopt the method of fixed investment, which is suitable for the public and not for the stock god.