The yield on the 2-year Treasury note topped 4.1% after the Federal Reserve raised interest rates by another 0.75 percentage point, and surged to its highest level since 2007.
The policy-sensitive 2-year Treasury rose 15 basis points to 4.113%, to a level not seen since October 2007 when it hit a high of 4.138%. Meanwhile, the yield on the benchmark 10-year Treasury rose to a high of 3.64%, its highest level since February 2011.
The significant inversion, with short-term rates higher than long-term rates, points to the risk of a recession, some investors believe.
Yields and prices move in opposite directions, and 1 basis point is equivalent to 0.01%.
The Fed raised rates by 75 basis points at its September meeting and signaled that it will keep hiking rates until the funds level hits a "terminal rate," or an end level of 4.6% next year.
The central bank plans to stay aggressive against inflation this year, raising rates to 4.4% in 2022, according to its median forecast released on Wednesday. With only two policy meetings left in the calendar year, chances are the central bank could conduct another 75-basis-point rate hike before the year-end.
"As a result, bond yield inversions continue to widen, causing equity markets to fall further as recession risks increase," CFRA's Sam Stovall said.
The 2-year rate started 2022 trading at around 0.73%. Wednesday's move puts it 328 basis points (3.28 percentage points) above that level.
— CNBC's Jeff Cox and Yun Li contributed to this report.