Personally, in the past two years, I have made a one-time purchase and invested in Shenzhen Stock Exchange 100. The profit of fixed investment is positive, and the one-time purchase is negative.
Of course, this has a lot to do with the stock market crash in the past two years. Now the stock market has just shown a trend of improvement (it is best to judge according to the stock market situation when buying funds, after all, our money is also used to buy stocks indirectly), so I think it is best to make a fixed investment now, because the stock market has a positive trend, which does not mean that it will only rise but not fall during the whole improvement process. At present, the stock market risk is still very high.
If you want to buy it once, you'd better wait and see for a while. After all, the market of 10 has just started.