10-year Treasury yield falls to the lowest since Dec. 2017 on global growth concerns

The yield on the benchmark 10-year Treasury note fell on Monday to its lowest level since December 2017 as fixed-income investors continued to worry about global growth and a potential deceleration in the U.S. economy.

Those fears kept the Treasury yield curve inverted during the session, with the yield on the 3-month bill above that of the 10-year note.The short-term rate first exceed that of several longer-term securities last week in a phenomenon known as inversion and viewed by many as a recession predictor.

The yield on the benchmark 10-year Treasury note, which moves inversely to price, was lower at 2.388 percent, its lowest since December 2017. The yield on the 2-year Treasury note was also lower at 2.233 percent while the 3-month yield was at 2.454 percent.

International fixed-income markets have also been affected since the Fed's commentary last week. Yields on both the German 10-year bund as well as the Japanese 10-year traded in negative territory Monday.

Inversion happens when investor expectations for growth recede. The yield curve normally slopes upward: Those that buy U.S. government debt in the form of bonds are compensated with better interest rates than those who loan money for a matter of months.

If traders believe Americans will produce fewer goods and services in two years than it will in two months, the curve can invert, or slope downward as more investors move into long-term debt and pivot elsewhere in the near-term.

That appears to be the case now, days after the Federal Reserve tempered U.S. growth forecast. The central bank added last Wednesday that it plans to cease its program of reducing the bonds and mortgage-backed securities on its balance sheet.

"The Fed has officially moved to the sidelines (so they're not the catalyst for higher rates, and could even cut if needed)," wrote George Goncalves, head of fixed-income strategy at Nomura Securities International.

"The rally's speed is suggestive that there was still a portion of market participants that were clinging to the hope of one more hike for the cycle. Some serious damage was done to technical charts too and rate levels," he added.

— CNBC's Sam Meredith contributed reporting.