Disadvantage 1: I can't earn more.

If you are a person with the ability to judge high and low points, you don't need to use fixed investment, because you can earn more by grasping high and low points.

Disadvantage 2: If the target continues to fall, it will still lose money.

In fact, if you buy something that has been falling, you will lose money. Even if the price is increased, the time cost should be considered, and the annualized rate of return may be very low.

Disadvantage 3: Not suitable for short-term operation.

Fixed investment is bought at average cost. As long as we talk about the concept of average value, it must be long-term, otherwise it will still be affected by the buying and selling prices in the short term.

Disadvantage 4: Too long will lead to failure.

For example, 3,000 yuan per month, 100 months later became 300,000 yuan. At this time, the impact of RMB 3,000 in the next month on the previous performance is only 1%, which can no longer achieve the effect of average cost. So it is usually decided to make a profit after a period of time.