XD means "ex-dividend", that is to say, investors who hold shares before this date will get a certain amount of dividends before the ex-dividend date, so the trading price of this stock will of course move down in parallel the next day.

Of course, stock dividends are not necessarily cash, such as stock dividends (that is, the news that a stock is often given two for ten).

In fact, cash dividend and stock delivery are equivalent to "cash dividend" and "dividend reinvestment" in the fund.

A supplementary knowledge is the pricing method of stock: "pre-recovery right" and "post-recovery right", that is, whether the stock price impact caused by these events is included in the actual transaction price "forward" or "backward". These historical stock prices seem to be smooth curves and constantly changing. The price without rights will appear "fault" and "jump" on the day of ex-dividend and ex-dividend.