The fixed-income vehicles still represent a hedge against a global economic slowdown.
The yield on the 30-year bond rose 16 basis points to around 3.19%, its highest level since December 2018.
Some market watchers wonder just how long the Fed can stick to a moderate approach.
Ten-year Treasury yields have room to run, she said, perhaps even to 4%.
Anxiety is building among money managers that stagflation, out-of-control inflation just as growth slumps, will eventually come to pass.
Two-year yields climbed 10 basis points to 2.44%.
The last persistent inversion of the Treasury curve occurred in 2006-2007, though it briefly inverted in 2019.
The Fed chair believes the central bank has plenty of room to aggressively jack up rates.
The bond markets suggest inflation will be a lingering concern for the long term.
Bond traders are growing increasingly concerned that the economy could buckle under the weight of monetary-policy normalization.