"Much of Mason's wealth comes from Groupon's stock. He owns 7 percent, or about 46 million shares, according to FactSet. Based on Thursday's closing price, that's worth more than $208 million."
The funny thing is he would have been much richer if he got fired much sooner. That would have given him an excuse to sell his stake before it tanked. Being the CEO meant he couldn't dump his stock.