That's an important--this really does happen, stocks really do drop in price on ex-dividend date.

这很重要,公司就是这么做的,股价通常会在除息日下跌

耶鲁公开课 - 金融市场课程节选

The answer is generally not because if you buy the stock before it goes ex-dividend, you get--you have to pay a higher price, but you get the dividend.

答案一般来说是不用,如果你买了股票,是在除息之前买的,你的买入价高,但能分到红

耶鲁公开课 - 金融市场课程节选

Some of these are still listed on The New York Stock Exchange page; on the day that a stock goes ex-dividend, they'll have a little "x" by its price.

有些还在纽约证交所的网页上,股票除息的那一天,股价前面会有个小小的"x"标记

耶鲁公开课 - 金融市场课程节选