Bill Gross, manager of the world’s biggest bond fund, said the Federal Reserve may be unable to calm volatility it triggered in global financial markets after it signaled an eventual cut in its monetary stimulus.

“I doubt they can put Humpty Dumpty back together again,” Pacific Investment Management Co.’s founder Gross said in a radio interview on “Bloomberg Surveillance” with Tom Keene and Mike McKee. Vice Chairman “Janet Yellen’s task was to damp volatility, to lower that term premium, to calm markets, and they did that. But now there is significant unrest.”

Chairman Ben S. Bernanke said Wednesday the Fed may start reducing bond purchases later this year and end the program in 2014 should risks to the U.S. economy abate. The Federal Open Market Committee forecasts the economy to grow 3 percent to 3.5 percent next year, driving the unemployment rate down to 6.5 percent to 6.8 percent from 7.6 percent in May.

Government debt around the world fell, with Treasury 10-year note yields climbing to a 22-month high of 2.47 percent Thursday, as investors priced in the odds of reduced monetary stimulus. Emerging-market assets dropped, with India’s rupee and Turkey’s lira touching record lows.

“The real economy won’t follow the path the Fed thinks it will,” said Gross. “The chairman suggested Wednesday that, once we get through this soft patch of fiscal austerity in the U.S., that the 3 percent growth number is indeed where we should be and where they expect we’ll be. We have our doubts at Pimco.”

Premium Rises

The excess return investors demand for holding longer-term Treasurys surged. The term premium on 10-year notes moved above zero for the first time since October 2011 and to the highest since July of that year, according to a Columbia Management Investment Advisers LLC model. The premium, which reached an all-time low of minus 0.64 percent in July, has been held down by Fed bond buying, inflation about half what it was two decades ago, and global demand for safe assets.

Bernanke also said at the news conference in Washington Wednesday that the rise in mortgage rates recently hasn’t been “so dramatic” as he suggested the housing market may be strong enough to withstand higher borrowing costs.

Yields on Fannie Mae’s 3.5 percent, 30-year securities have soared 0.4 percentage point in the past two days to a 19-month high of 3.1 percent.

“The chairman was rather dismissive in terms of mortgage rates,” Gross said. “To dismiss that increase in costs based on higher interest rates I think is not only dismissive but again not reflective of what may lie ahead in terms of housing prices and the real economy.”

The rise in mortgage rates this year has increased the average monthly payment for a new home by 20 percent to 25 percent, according to Gross.