The core idea
Bid-ask spreads widen when market makers face greater uncertainty, inventory risk or difficulty hedging a position.
What is happening underneath
Lower trading activity and stressed funding conditions can amplify the effect.
How investors should read it
A wider bid-ask spread is effectively a higher transaction cost and a direct sign of weaker liquidity.
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.