Federal authorities are examining a series of well-timed trades made by the golfer Phil Mickelson and the gambler William T. Walters, people briefed on the investigation said, focusing on trading in two different stocks. The authorities are also questioning what role, if any, the investor Carl C. Icahn may have had in sharing information about one of the stocks: the consumer products company Clorox.
Mr. Mickelson, a three-time winner of the Masters golf tournament and one of the country’s highest-earning athletes, placed his Clorox trade in 2011, the people briefed on the investigation said. Mr. Walters, an owner of golf courses who is often considered the most successful sports bettor in the country, made a similar trade about that time, the people added.
Mr. Icahn, a 78-year-old billionaire and one of the best-known investors in the world, was mounting a takeover bid for Clorox around the time that Mr. Mickelson and Mr. Walters placed their trades.
The F.B.I. and Securities and Excha
