Vikram Rai of Wells Fargo is dubious of some widely-held assumptions.

"Decelerating or slowing economic growth has sparked a classic flight-to-quality trade with short-term Treasuries being the prime beneficiary," said Gary Pzegeo, head of fixed-income at CIBC Private Wealth U.S.

All eyes now turn to the September Federal Open Market Committee meeting where the Fed is expected to cut rates, but market participants are mixed on whether it will be a 25- or 50-basis-point cut.

"The Fed remains data dependent as always, but it now appears that the 'more good data' bar is not as high as it was before, particularly with labor market developments becoming more important," said Michael Gregory, deputy chief economist at BMO Economics.

Economists expect the FOMC to hold rates, although some say there's a case to be made for a July cut, with Fed Chair Powell setting the table for September.

The Fed chief said "more good data" is needed before interest rate targets are lowered.

All eyes are on the Federal Reserve as the wait for rate cuts continues. Steve Skancke, chief economic advisor at Keel Point, will discuss the Federal Open Market Committee meeting, the Summary of Economic Projections, and Chair Powell's press conference.

Ransomware group LockBit threatened on Sunday to publish the stolen data Tuesday evening. Ransomware experts said it was likely that the group was bluffing.

"It is hard to be overly excited about current valuations of tax-exempts relative to Treasuries; however, at tax-adjusted yields (using individual tax brackets), munis look quite attractive compared with other asset classes," noted Barclays PLC.

Municipal bond mutual funds saw small inflows as investors added $16.4 million to the funds after $154.4 million of inflows the week prior, according to LSEG Lipper.