The core idea
Yes. Bond yields can be negative when investors are willing to pay a price that implies receiving less nominal money than they invest if the bond is held under the assumed cash-flow path.
What is happening underneath
This occurred across parts of European and Japanese government-bond markets during the negative-rate era.
How investors should read it
Investors may still hold negative-yielding bonds for liquidity, regulation, hedging, collateral or expectations of further price gains.
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.