Domino's Pizza trades at records Wednesday, popping into positive territory after Bill Ackman, who runs hedge fund Pershing Square Capital, said he had taken a 6% stake in the pizza franchise. Ackman was speaking at a virtual event hosted by the Wall Street Journal, called the Future of Everything Festival. Shares of Domino's were at $437, surprassing its May 4th record at $433.99, FactSet data show. Market Pulse Stories are Rapid-fire, short news bursts on stocks and markets as they move. Visit MarketWatch.com for more information on this news.