Even the fast money has been caught off-guard by the latest leg of a relentless bond rally that’s stumping traders and strategists across Wall Street.

Data on positioning among the biggest leveraged traders, the ranks of which are dominated by hedge funds, show the cohort has been increasing bets against longer-dated Treasuries for weeks, setting up for the reflation trade to get back on track as data points to an economic resurgence.

Instead, U.S. bonds have surged, with the yield on 10-year Treasuries hitting the lowest since February on Monday. It’s on track to fall for a fourth-straight month—something that hasn’t happened since the pandemic hit.

The resilience is a surprise because Treasuries should typically sell off in an environment of economic expansion and inflation. The latest reports have pointed to surging price growth and stronger-than-forecast retail sales in the U.S., yet as new coronavirus cases climb and the reopening proves uneven, yields have continued to decline—wrong-footing half of Wall Street.

“The market appears to be looking further ahead to an eventual return to contained inflation and growth,” said Robert Tipp, chief investment strategist and head of global bonds for PGIM Fixed Income, which oversees about $968 billion.

That’s turning into a problem for some hedge funds. Combined net-short positions for leveraged funds in 20- and 30-year Treasury futures climbed to the highest since February last week, according to the latest data from the Commodity Futures Trading Commission.

Yields for those notes have dropped around 50 basis points each in the past two months.

Of course, that kind of rally is hard to sustain—meaning funds may now be well-placed for any reversal. Meanwhile, these speculators aren’t necessarily taking a blanket bet against Treasuries.

Data also show leveraged players are net long on 10-year notes. That suggests they hold a more nuanced view—that growth and inflation will impact mostly longer-dated bonds.

Regardless, for now it’s proving to be a bad time to bet against most U.S. debt. The yields on 20- and 30-year notes were both down at least 7 basis points as of 7:47 a.m. in New York. The 10-year yield fell 6 basis points to 1.227%.

“I believe we’ve seen the peak in yields for this cycle,” Tipp said. “With the resumption of the long-term bull market I think it’s going to be difficult to make money being short bonds.”

This article was provided by Bloomberg News.