[1]https://www.cnbc.com/2017/11/22/peter-thiel-sells-majority-o...
So, not a huge amount of Facebook nor of his net worth, but still a huge amount of money. I'm not sure how billionaires think, but I suspect to become a billionaire it's usually not "I won't sweat a loss of couple tens of millions of dollars."
Our "billionaire" president paid his son's Boy Scouts fees with charity money rather than his own. People with that kind of money are usually SUPER cheap and REALLY attached to every dollar.
all things being equal, I'm sure he would care at least a little about a seven or eight figure loss, but I'm not sure it would be worth the opportunity cost of neglecting his other investments.
So about $24M at today’s price.