Billionaire hedge fund manager Bill Ackman believes long-term Treasury yields can shoot even higher in the short run on the back of stubborn inflation.

“I would not be shocked to see 30-year rates through the 5% barrier, and you could see the 10-year approach 5%,” he told CNBC’s Scott Wapner at the CNBC Delivering Alpha Investor Summit on Thursday in New York City.

The Pershing Square Capital Management CEO said he did not believe the Federal Reserve could get inflation back down to its 2% target partly due to a resurgent labor movement and high energy prices.

“Our view is that we’re in a different world,” the investor said. “You have a generation of people that are used to rates, you know, four sounding like a high interest rate. On a historical basis, it’s an extremely low rate of interest.”

The benchmark 10-year Treasury yield hit a 15-year high this week, topping 4.65%, as the Federal Reserve signaled higher interest rates for longer this month. The 30-year rate last traded around 4.71%.

Still, Ackman said buying the 30-year Treasury bond isn’t worth locking up your money for that long with inflation eating into its return.

“We have an economy that is still strong and inflation at 3.5%, 4%, persistent,” Ackman said. “Our view is basically you’re not being paid enough to enter into a 30-year contract with this government.”