First hit on Google. "An individual who has achieved a high net worth as a result of the large total market value of the assets he or she owns. This phenomenon

First hit on Google. "An individual who has achieved a high net worth as a result of the large total market value of the assets he or she owns. This phenomenon usually occurs when investors buy marketable securities that are later bid up to much higher prices on the open market. While this creates large amounts of "paper profit", the paper millionaire's riches usually aren't safe until these holdings are liquidated."