The practice of selling dividends is prohibited because:

Selling dividends is prohibited primarily because dividends are already reflected in the fund's price, meaning that selling them can create confusion among investors. When a fund pays dividends, this amount is typically taken out of the fund's net asset value (NAV), which can mislead investors about the true value of their investment. By representing dividends as a separate sellable entity, it could give the incorrect impression that they are an additional value rather than a distribution of the fund's existing assets. This practice could encourage misinterpretation of investment performance and lead to misguided investment decisions based on the perceived availability of "easy" income from dividends.

Furthermore, the intricacies of how dividends interact with a fund's pricing structure can lead to potential misunderstanding among investors about the actual performance and value of their investments. Hence, this prohibition is in place to protect investors and ensure they have a clear understanding of their holdings.