The core idea
Treasury yields affect stocks because they influence discount rates, financing costs and the return investors can earn on lower-risk assets.
What is happening underneath
Higher real yields can reduce the present value of distant corporate cash flows and make bonds more competitive with equities.
How investors should read it
The relationship is not fixed: yields can also rise because growth expectations improve, which may support earnings.
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.