1. The principal invested in the previous period will be returned soon, either by borrowing money to appease the investor's mood or by returning only part of the principal.

2. The sudden emergence of a large number of activities and short-term investment opportunities may be to attract new investors' funds and give high returns to previous investors.

3. The capital sector often promises to return the principal, and even promises to double the return, which makes investors feel that the risk is relatively low.

4. Investors may be encouraged to participate in high-risk investments, such as futures and stocks, so as to ensure the defendant to obtain high profits.

5. The fund market will suddenly collapse, resulting in investors not getting due returns or principal.