The sharp fall in U.S. Treasury yields this year has taken many by surprise, and some traders are now looking for the exits amid concern that a correction is looming.
"The kitchen is about to heat up and we want out now," Morgan Stanley said in a note Friday.
It believes expectations the European Central Bank (ECB) will take fresh easing measures are behind the decline in Treasury yields over April and May and that the central bank's policy decision on Thursday will mark the low for yields.
"Investors have been lured into Treasurys by ECB President Draghi's honey-sweet siren song. Strap yourself to the mast and increase duration underweights ahead of the ECB," it said.
In addition to the ECB, traders have pointed to a variety of factors including short-covering spurred by a "bear squeeze" and a flight to safety amid global economic jitters for the rally in U.S. Treasury prices, which move inversely to yields.
After touching 11-month lows of 2.44 percent last week, U.S. 10-year Treasury yields had edged up to 2.49 percent by early Monday, well off the highs of around 3.0 percent touched in early January.