A billionaire is a person with a net worth of at least one billion (1,000,000,000, i.e., a thousand million) units of a given currency, usually of a major currency such as the United States dollar, the euro, or the British pound. The American business magazine Forbes produces a global list of known U.S. dollar billionaires every year and updates an Internet version of this list in real time. The American oil magnate John D. Rockefeller became the world's first confirmed U.S. dollar billionaire in 1916, and still holds the title of history's second wealthiest individual.
As of 2018[update], there are over 2,200 U.S. dollar billionaires worldwide, with a combined wealth of over US$9.1 trillion, up from US$7.67 trillion in 2017. According to a 2017 Oxfam report, the top eight richest billionaires own as much combined wealth as "half the human race". In the 2020s, several people have become U.S. dollar centibillionaires, meaning that each has had a net worth of at least $100 billion.
See also: The World's Billionaires
According to the UBS/PwC Billionaires Report 2019 report released in November 2019, there are currently 2,101 U.S. dollar billionaires worldwide, from 66 countries, with a combined net worth of $8.5 trillion. The majority of billionaires are male, as fewer than 11% (197 of 1,826) on the 2015 list were female billionaires. The United States has the largest number of billionaires of any country, with 536 as of 2015[update], while China, India and Russia are home to 213, 90 and 88 billionaires, respectively. As of 2015[update], only 46 billionaires were under the age of 40, while the list of American-only billionaires, as of 2010, had an average age of 66.
In 2019 there were a record 607 billionaires in the U.S. This group includes 14 of the world's 20 richest people. Jeff Bezos was number 1 in the world, followed by Elon Musk, and Bernard Arnault and family at number 3. In January 2021, Musk ascended to the top of the list.
Billionaires come from a very wide number of backgrounds. A review of the education and work histories of the top 400 Billionaires shows little correlation between education and success. Nearly 30% of Billionaires do not have a college degree, greatly exceeding any other educational background. The most common field of university education was finance and economics, which only contributed to a combined 15.5% of Billionaire educations.
There is little correlation between any university and becoming a Billionaire. The top 10 Universities produced just 99 of the top 400 Billionaires combined, significantly less than the total number of Billionaires who were not college educated. Military service produced 21 Billionaires, more than any single University. 
Very few college educated Billionaires went on to use their degrees except for computer science majors. All 12 of the 12 computer science majors worked in computer science, while only half of Engineers worked in Engineering, and less than a quarter of finance and economics majors ever worked in finance or economics. The most common field for Billionares to enter was sales and military service.
See also: Ultra high-net-worth individual
According to a 2016 Oxfam report, the wealth of the poorest 95% dropped by 38% between 2010 and 2015, due to an increase in the global population of 400 million. In the same period, the wealth of the richest 62 people between the World's Billionaires increased by $500bn (£350bn) to $1.76tn. More recently, in 2017 an Oxfam report noted that just eight billionaires have as much net worth as "half the human race". However, the Oxfam report has been criticized for considering debt as negative wealth, which leads to wealthy people with large amounts of debt to be considered poor or not wealthy.
In 2019, 19 people became billionaires. Four of the members joined as a result of death or divorce, including Julia Koch and Jeff Bezos's former wife Mackenzie Bezos.
New members now also include more and more women. In the last five years, the number of female billionaires has grown by 46 percent, that is more than the number of male billionaires in the same period (39 percent). There are now 233 female billionaires in the world, a steep growth from 160 in 2013.
The table below lists numerous statistics relating to billionaires, including the total number of known billionaires and the net worth of the world's wealthiest individual for each year since 2008. Data for each year is from the annual Forbes list of billionaires, with currency figures given in U.S. dollars. Data since 2018 also includes the Wealth-X billionaire census which typically finds higher numbers than Forbes.
|Year||Total number of
|Combined wealth of
|Number of billionaires||World's wealthiest
|2019||2,153-2,604||$8.6-$8.7 trillion||609-705||285-324||98-102||82-106||Jeff Bezos||$131 billion|
|2018||2,208-2,754||$9.1-$9.2 trillion||585-680||338-372||96-111||117-119||Jeff Bezos||$133 billion|
|2017||2,043||$7.71 trillion||565||319||106||101||Jeff Bezos||$99.6 billion|
|2016||1,810||$6.48 trillion||540||251||75||90||Bill Gates||$75 billion|
|2015||1,826||$7.05 trillion||536||213||88||88||Bill Gates||$79.2 billion|
|2014||1,645||$6.4 trillion||492||152||111||56||Bill Gates||$78 billion|
|2013||1,426||$5.4 trillion||442||122||110||–||Carlos Slim||$73 billion|
|2012||1,226||$4.6 trillion||425||95||96||–||Carlos Slim||$73 billion|
|2011||1,210||$4.5 trillion||413||115||101||–||Carlos Slim||$74 billion|
|2010||1,011||$3.6 trillion||404||89||62||–||Carlos Slim||$53.5 billion|
|2009||793||$2.4 trillion||359||28||32||–||Bill Gates||$40 billion|
|2008||1,125||$4.4 trillion||470||–||87||–||Warren Buffett||$62 billion|
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