The core idea
Stocks can rise when bond yields fall because lower discount rates increase the present value of future corporate cash flows and reduce financing costs.
What is happening underneath
But yields may also fall because growth expectations collapse, which can hurt equities.
How investors should read it
The cause of the yield decline determines whether lower rates are supportive for stocks.
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.