Billionaire investor Bill Ackman.Brian Snyder/Reuters Billionaire investor Bill Ackman revealed he's betting against 30-year US Treasurys. The Pershing Square chief said he's short due to to the impact of higher interest rates on stocks. "The best hedges are the ones you would invest in anyway even if you didn't need the hedge," he said. Bill Ackman revealed he's betting against US Treasurys as a hedge against stubbornly high inflation.