Don't forget that he is a businessman, and he is also the richest man in the world. If he were stupid enough to sell his fortune at a loss, he wouldn't be the richest man on the planet.
Just because he is rich and smart doesn't mean that he can't make mistakes that will cost him money. Take for example those 3AC and Celsius people; those are smart (and rich) people that were blinded by greed and made stupid mistakes. All I am saying is that its wrong to judge this move (and gloat) based on the price when this news leaked because both of these things happened earlier.