The most powerful government bond market rally in years is showing signs of petering out. Investors appear increasingly reluctant to pay up for pricey Treasuries and they’re showing a nascent appetite for risk. The turnaround remains in the early stages and could quickly reverse itself, yet even now some significant pain is being felt among bond mavens.

U.S. Treasuries hit their high-water mark on March 17, the day before the Federal Reserve’s latest interest rate cut, with yields on two-year Treasury notes ending at 1.33 percent, their lowest since July 2003. The Fed’s 75-basis-point reduction the next day disappointed many bond investors, especially those hunkered down at the front end of the yield curve where Fed policy expectations are paramount.

Up to that point, the JPMorgan government bond index had notched a total return of more than 15 percent since mid-June 2007, when worries about the subprime mortgage market collapse set the Treasuries market on fire. The net total return on the benchmark S&P 500 over the same run? Negative 14 percent.

Since March 17, though, bonds are broadly lower and stocks are up 7.6 percent. JPMorgan’s index of shorter-dated Treasuries, with durations from one to three years, has fallen 0.88 percent over the past three weeks. At a glance that may not seem a horrific performance. Nonetheless, that is the index’s worst slump over a similar stretch in four years. The last time it fared so poorly in such a short time? Spring 2004, when bonds sold off just before the Fed embarked on a two-year rate-hiking campaign.