Belief Perseverance is the tendency to maintain an initial belief even after encountering information that weakens or contradicts it [1].

Belief perseverance is the tendency to maintain an existing belief even after new evidence weakens or contradicts it. In financial markets, traders often continue defending an original thesis because changing their minds feels more psychologically costly than remaining committed to it.

Canonical source: Ross, Lepper, & Hubbard (1975)