The Saphead (1920)

Nick Van Alstyne owns the Henrietta silver mine and is very rich. His son Bertie is naive and spoiled. His daughter Rose is married to shady investor Mark. Mark wrecks Bertie's wedding plans by making him take the blame for Mark's illegitimate daughter. Mark also nearly ruins the family business by selling off Henrietta stock at too low a price. Bertie, of all people, must come to the rescue on the trading floor.