For the year, though, the stock was up more than 300%. A mid-month civil trial loss by Chemours’ former parent company, DuPont There wasn’t a single clear reason for the stock’s sharp December decline, although stocks of other companies selling titanium dioxide like Kronos and Tronox were down more modestly: One major event that could have a big impact on the company came mid-month, as DuPont was found liable in a civil trial related to the company’s manufacture of the toxic chemical PFOA.