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.
Investopedia explains 'Paper Millionaire'
It is important to note that paper millionaires are not the same as true millionaires, which generally refers to people who have more than $1 million in cash in the bank.
For example, consider a hypothetical investor during the 1990s technology bubble who invested in startup dotcom companies. Assuming that none of this investor's shares is sold, he or she would have become a paper millionaire, as recorded on the brokerage statement, despite having very little cash in the bank.
However, once the dotcom bubble burst, technology stocks saw their share prices collapse, and former paper millionaires once again found themselves poor, owning only pieces of paper (i.e. share certificates) that were no longer worth the millions of dollars at which the market had previously valued them.
Many people aspire to being a millionaire but not so many are prepared to put in the effort and to change their mindset to achieve this milestone. In a world where being a billionaire is now the new target for the rich, becoming a millionaire is a real possibility for many an average Joe and it mostly comes down to good management, sensible thinking and occasional calculated risks.
Becoming a millionaire won't happen simply by sitting there and praying for money or entering the lottery every week and it won't happen by simply reading how to make it happen – after learning what tools to use and mindset to adopt, the rest of the real effort is up to you actually doing something to achieve this