Betting against U.S. government debt this year is turning out to be a fool’s errand. Just ask Wall Street’s biggest bond dealers.

While the losses that their economists predicted have yet to materialize, JPMorgan Chase & Co., Citigroup Inc. and the 20 other firms that trade with the Federal Reserve began wagering on a Treasuries selloff last month for the first time since 2011. The strategy was upended as Fed Chair Janet Yellen signaled she wasn’t in a rush to lift interest rates, two weeks after suggesting the opposite at the bank’s March 19 meeting.

The surprising resilience of Treasuries has investors re- calibrating forecasts for higher borrowing costs as lackluster job growth and emerging-market turmoil push yields toward 2014 lows. That’s also made the business of trading bonds, once more predictable for dealers when the Fed was buying trillions of dollars of debt to spur the economy, less profitable as new rules limit the risks they can take with their own money.

“You have an uncertain Fed, an uncertain direction of the economy and you’ve got rates moving,” Mark MacQueen, a partner at Sage Advisory Services Ltd., which oversees $10 billion, said by telephone from Austin, Texas. In the past, “calling the direction of the market and what you should be doing in it was a lot easier than it is today, particularly for the dealers.”

Treasuries have confounded economists who predicted 10-year yields would approach 3.4 percent by year-end as a strengthening economy prompts the Fed to pare its unprecedented bond buying.

Caught Short

After surging to a 29-month high of 3.05 percent at the start of the year, yields on the 10-year note have declined and were at 2.72 percent at 7:42 a.m. in New York.

One reason yields have fallen is the U.S. labor market, which has yet to show consistent improvement.

The world’s largest economy added fewer jobs on average in the first three months of the year than in the same period in the prior two years, data compiled by Bloomberg show. At the same time, a slowdown in China and tensions between Russia and Ukraine boosted demand for the safest assets.

Wall Street firms known as primary dealers are getting caught short betting against Treasuries.