Billionaire hedge fund manager Bill Ackman once again urged the Federal Reserve to tamp down surging inflation by committing to keeping higher rates for longer without signaling a plan to reverse course. "The biggest risk to the US economy is not the Fed raising rates. It is inflation which is hurting consumer and business confidence and pricing consumers out of a new home, a car, gas and meals on the table," Ackman said Tuesday in a series of tweets. "The Fed understands this and therefore I expect [Fed Chair Jerome] Powell will show hawkish resolve on not only maintaining higher rates for longer, but also being open to a terminal rate meaningfully higher than 3.4%," he added. The Fed is widely expected to raise interest rates by another three-quarters of a point Wednesday, putting the fed funds rate in a range of 2.25% to 2.5%. The Fed started lifting rates from near zero in March to combat inflation that has reached levels not seen in four decades. The Pershing Square hedge fund manager believes inflation has become embedded in the economy and is top of mind of every American. The consumer price index soared 9.1% in June from the year-earlier period, above the 8.8% Dow Jones estimate. It was the steepest rise since November 1981. Ackman said it's likely Powell will be asked about the timing for cutting rates, adding that it's important for him to signal the central bank's willingness to stay the course and aggressively hike rates until inflation is under control. "The more the market believes that the Fed will immediately reverse course, the less effective raising rates will be in moderating inflation, and the more the Fed will have to raise rates," Ackman said. This isn't the first time the high-profile investor has publicly called on the Fed to act seriously to control raging inflation. He previously said that markets will soar once investors can be confident that the days of runaway inflation are over.