In order to protect the interests of A share holders and avoid excessive leverage of B share net value (the CSRC stipulates that it shall not exceed 6 times); Most graded funds have designed an irregular downward conversion mechanism. The treatment method is to trigger downward irregular discount (hereinafter referred to as "downward discount") when the enterprising net value falls to a certain threshold (the threshold set by different products is between 0.2 and 0.3 yuan, mostly 0.25 yuan). The net fund shares of A share, B share and parent fund share will all be adjusted to 1 yuan. After the adjustment, the steady share and the enterprising share will be retained according to the initial proportion, and the rest after the A share and the B share are paired will be converted into the parent fund's on-site share and distributed to the A share investors.