Unforseen

Okay, perfect. Next question which is more interesting to me.  If we know for a fact that the stock price will drop by the PV of the dividend amount, why can’t we just short the stock right before market close the day before Ex-Dividend and buy back market open on Ex-Dividend?
My guess is this:  the stock price will always drop by the amount of the dividend, but we won’t know the net change in stock price when combined with other things that might cause the stock price to go up.  I still wonder if anyone has ever tried to short all stocks right before Ex-Dividend and bought them back on Ex-Dividend if you could end up with a net gain… everyone knows it’s going to drop on that day though, so I doubt it.