For a portfolio or a fund, you need to consider two points when choosing between a one-time purchase or a fixed investment: first, your own capital situation, and second, the volatility of the product itself.

Situation 1: If the funds you want to invest are similar to salary balances, and a fixed amount is received every month, then no matter what product you invest in, you can only use fixed investment.

?After all, you can’t get your future salary in advance and buy it in one go.

In this case, fixed investment is a good choice. It can help you restrain consumption and cultivate investment discipline.

It's a bit like when we were children, we put some steel jumpers into the piggy's belly every month, but now it has become an asset that we exchange money for some stocks or bonds every month.

Situation 2: Another situation is that you have a large amount of funds on hand that you want to invest. At this time, is it better to buy it all at once, or to divide it into several monthly fixed investments?

?This requires considering the volatility of the product.

1. Fixed investment can be used for products with high volatility, such as index funds, partial stock funds, heavy equity fund portfolios, etc.

?The perfect situation is to buy at a "low point", but most people do not have such ability, so they can only settle for the next best thing and choose to buy with fixed investment to obtain an average cost.

2. But for products with low volatility, fixed investment is not required.

?Imagine if you have a sum of money and want to buy a bank deposit, how many times will you buy it?

?Obviously not.

?For products that are steadily growing, the earlier you invest your funds, the more benefits you will enjoy.

Taking "a certain all-weather strategy combination" as an example, we have calculated the following three buying plans: Starting from January 1, 2019: A. A one-time investment of 40,000 yuan; B. A fixed investment of 1,000 yuan every two weeks.

***In the 42nd period, the total investment is 42,000 yuan; C. The monthly fixed investment is 2,000 yuan. ***In the 21st period, the total investment is 42,000 yuan.

For these three experimental accounts, as of September 30, 2020, account A has 50,608 yuan, account B has 47,403 yuan, and account C has 47,520 yuan.

The annualized yields are not much different, which are 14.42%, 14.25% and 14.26% respectively; the cumulative yields are 26.52%, 12.86% and 13.14% respectively.

The product is the same, the time period is the same, and the final annualized rate of return is basically the same, but the cumulative rate of return from the fixed investment is almost half of the one-time purchase.

?This is because the fixed investment money is invested in the product bit by bit, and the time cost is only half of that of a one-time purchase.

It can be seen that for products with low volatility, there is no need to use fixed investment to buy them.

?As long as your capital usage cycle and acceptable drawdown are consistent with the product objectives, there is no need to time the investment and you can buy it all at once.

?If the amount of funds is large and you feel uncomfortable if it falls after buying it, then investing 1/3 every month for three months is enough.