The closed period of the fund means that the fund has successfully raised enough funds. After the fund contract comes into effect, investors' applications for fund share redemption will not be accepted for some time. According to the regulations, the fund can not be closed for more than 3 months.
On the one hand, the fund closure period is to facilitate the fund backstage and make full preparations for subscription and redemption, on the other hand, it also gives the fund manager a certain time to make preliminary arrangements for the raised funds according to market conditions.