The core idea
Quantitative tightening returns more duration to private investors and can reduce central-bank liquidity, potentially increasing the yield required to absorb bond supply.
What is happening underneath
The effect is not mechanical because issuance, reserve demand, policy expectations and risk sentiment also change.
How investors should read it
QT is best understood as one part of the overall supply and liquidity environment.
The same market move can carry different information depending on which maturity, issuer and risk premium is changing. Read the question together with the underlying concepts rather than treating one price move as a universal signal.