"Bill Ackman used his vast wealth to worm his way into a professional, ATP-sanctioned tennis tournament at the Hall of Fame at the age of 59," journalist Glenn Greenwald posted on X. "His level was so abysmal that it forced the professional players on the court to pat the ball to him, enraging the tennis world."

Billionaire Bill Ackman has been mocked online following his pro-tennis debut at the Hall of Fame Open doubles tournament in Newport, Rhode Island, with former tennis player Andy Roddick calling it the "biggest joke" he'd seen in the sport.

The 59-year-old hedge fund titan made his pro-tennis debut in a competitive ATP doubles tournament alongside a Grand Slam champion, and it ended in a straight-set defeat.