The core idea
Pension funds often hold long-duration bonds because their liabilities extend many years into the future.
What is happening underneath
Long bonds can help match the interest-rate sensitivity of promised pension payments.
How investors should read it
This liability-driven demand can influence the long end of government and high-quality credit curves.
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.