The total share of the fund is not fixed, because open-end funds are subscribed and redeemed by investors every trading day. The total share of closed-end funds is fixed.
The change of the total share of the fund has nothing to do with the rise and fall of the fund, and it has nothing to do with the dividend of the fund. If investors choose to reinvest in dividends, the share of funds held by investors will increase accordingly.
When investors invest in a fund, if the total share of the fund grows too fast, it is generally because the performance of the fund is very good and more investors subscribe. However, this has also brought great adjustments to fund managers, and investors need to be cautious.