overvaluation

/ˌoʊvərˌvæljuˈeɪʃən/
noun
  1. The act of giving something a value or importance that is too high; an estimate that is greater than the true worth.
    • Historians warn against the overvaluation of a single event in explaining a war.
    • The overvaluation of his skills made him overconfident in the job interview.
    • The overvaluation of the company's stock led to a sharp drop when profits were reported.
Synonyms