Meanwhile, Carlos Slim — Mexican business icon and former No. 2 — dropped to fourth after losing over $27 billion in 2015.
More than 220 people lost their billionaire designation, while 198 newcomers gained it. Overall, the combined net worth of the world's billionaires is down $570 billion this year.
Facebook CEO Mark Zuckerberg should get the title of "most improved" billionaire, though, jumping from No. 16 all the way to No. 6.
RELATED: 16 billionaires who inherited their fortunes
16 billionaires who inherited their fortunes
World billionaire rankings remind us how filthy rich these people are
16. Laurene Powell Jobs
Net worth: $14.4 billion
The widow of Apple cofounder Steve Jobs, Laurene Powell Jobs inherited his wealth and assets, which included 5.5 million shares of Apple stock and a 7.3% stake in The Walt Disney Co., upon his death. Jobs' stake in Disney — which has nearly tripled in value since her husband's death in 2011 and comprises more than $12 billion of her net worth — makes her the company's largest individual shareholder.
Though she's best recognized through her iconic husband, Jobs has had a career of her own. She worked on Wall Street for Merrill Lynch and Goldman Sachs before earning her MBA at Stanford in 1991, after which she married her late husband and started organic-foods company Terravera. But she's been primarily preoccupied with philanthropic ventures, with a particular focus on education. In 1997, she founded College Track, an after-school program that helps low-income students prepare for and enroll in college, and in September she committed $50 million to a new project called XQ: The Super School Project, which aims to revamp the high-school curriculum and experience.
Last October, Jobs spoke out against "Steve Jobs," Aaron Sorkin's movie about her late husband that portrays him in a harsh light, calling it "fiction." Jobs had been against the project from the get-go, reportedly calling Leonardo DiCaprio and Christian Bale to ask them to decline roles in the film.
(Photo by Stephen Lam/Getty Images)
15. Azim Premji
Net worth: $16.5 billion
In 1966, 21-year-old Azim Premji dropped out of Stanford in the wake of his father's death to take the helm of his father's company Western India Vegetable Products — later renamed Wipro. It was under Premji's leadership that the company diversified into toiletries and bath products and, eventually, IT, and the company grew exponentially. Now India's third-largest IT giant, Wipro generated revenues of $7.6 billion in its most recent fiscal year.
Just days into the new year, Premji named Abidali Neemuchwala, a Dallas-based consultancy executive, the new CEO of Wipro, citing him as the best leader to take Wipro into "its next phase of growth." Neemuchwala had been brought on to Wipro as chief operating officer last April after years of working for rival Tata Consultancy Services.
Premji is known for his generosity. He signed the Giving Pledge, committing to donate at least half of his wealth to charity, and in 2015 was named "the most generous Indian" on the Hurun India Philanthropy list for the third year in a row.
(Photo by Aniruddha Chowdhury/Mint via Getty Images)
14. Dieter Schwarz
Net worth: $20.9 billion
Dieter Schwarz joined his father's food-wholesaling business in 1973 and opened the company's first discount supermarket shortly thereafter. He took over as CEO when his father died in 1977 and rapidly expanded the business outside Germany, rebranding the company as Schwarz Gruppe.
The parent company umbrellas Lidl, a successful grocery-store chain and the second largest in Germany behind Aldi, and Kaufland, a chain of "hypermarket" stores similar to Walmart. Lidl has nearly 10,000 stores across 26 European countries and is set to break ground on US soil in 2018. Schwarz Gruppe now pulls in $85 billion in annual sales.
The German billionaire lives a quiet life out of the spotlight with his wife and two kids in their hometown of Heilbronn. He's reportedly a generous donor to educational causes.
(Photo by Ashok Saxena, Alamy)
13. Georg Schaeffler
Net worth: $22.2 billion
Georg Schaeffler served in the German military and held a short career in corporate law in the US before jumping aboard his father's company, Schaeffler Group, the nearly $11 billion (in sales) ball bearings and auto-parts maker that Schaeffler now co-owns with his mother.
The company made a splash in 2008 with its $17 billion hostile takeover attempt of tire and auto-parts maker Continental AG, which went south and left Schaeffler Group saddled with debt that it's managing to this day. It still owns a nearly 50% stake in Continental.
Schaeffler Group has recently invested nearly $550 million in its electric and hybrid car parts business, and it expects to double the number in the next five years.
(Photo by Hannelore Foerster/Bloomberg via Getty Images)
12. Alwaleed bin Talal bin Abdul Aziz al Saud
Net worth: $22.5 billion
Country: Saudi Arabia
Industry: Diversified investments
Prince Alwaleed comes from royalty — he is the grandson of Abdul Aziz al Saud, the first ruler of the Kingdom of Saudi Arabia — but he also built his fortune with savvy investments in a range of companies across the US and the Middle East. He founded Kingdom Holding Co. in 1980 and has since invested in everything from real estate to entertainment to education, with stakes in companies like Twitter, The Four Seasons, Time Warner, and Motorola.
Recently, Prince Alwaleed also made a play for ride-hailing service Lyft, reportedly grabbing a 2.3% stake by putting up $105 million of a nearly $250 million round of funding the company raised in December.
Prince Alwaleed has an enigmatic relationship with his money. In 2013, he sued Forbes for allegedly underestimating his wealth. But last summer he announced plans to donate his entire fortune to charity anyway.
(Photo by Pool Interagences/Gamma-Rapho via Getty Images)
11. Mukesh Ambani
Net worth: $24.8 billion
Industry: Petrochemicals, oil, and gas
Mukesh Ambani took over as chairman of Reliance Industries when his father, the company's founder, died in 2002. The enormous industrial conglomerate generates $62 billion in annual revenue from its interests in energy, petrochemicals, textiles, natural resources, retail, and, more recently, telecommunications.
Ambani is the richest person in India with a personal fortune of over $24 billion. He owns a 27-story Mumbai mansion that cost $1 billion to build.
And if Ambani's projections for India's economy prove correct, expect that net worth to soar. Four years ago, Ambani predicted that India would grow from a $1.4 trillion economy in 2011 to a $30 trillion economy by 2030 — a bullish estimate considering that India's GDP today stands at $2.2 trillion.
(Photo by Pradeep Gaur/Mint via Getty Images)
10 through 8. Forrest, Jacqueline, and John Franklyn Mars
Net worth: $28.6 billion each
Age: 84, 76, and 80
Siblings Forrest, Jacqueline, and John Franklyn "Frank" Mars inherited a stake in the iconic candymaker Mars Inc. when their father, Forrest Sr., died in 1999. The notoriously private trio co-own but don't actively manage the maker of M&M's and Milky Way bars, which their grandfather started in 1931 as a confectionary business in his kitchen in Tacoma, Washington.
In 2008, Mars Inc. branched out from chocolate to gum, when it acquired the Wrigley Jr. Co. for $23 billion. Since then, it's delved into pet food, buying Iams and two other brands in 2014 from Procter & Gamble for close to $2.9 billion.
Together the three siblings run the Mars Foundation, which gives primarily to educational, environmental, cultural, and health-related causes. In March 2015, Frank Mars was made an honorary knight by Queen Elizabeth II.
(Photo by Spencer Platt/Getty Images)
7. Bernard Arnault
Net worth: $28.9 billion
Industry: Luxury goods
Bernard Arnault's LVMH houses 70 luxury brands from Louis Vuitton to Hennessy to Dom Perignon, all controlled by family parent company Groupe Arnault. By the 1980s and '90s, Arnault, who started out as a civil engineer, had assumed control of the family business and proceeded to buy high-end fashion house Christian Dior, reviving it from the brink of bankruptcy. Like most LVMH brands today, Dior once again thrives as an industry standard bearer, helping the firm haul in a record $33 billion in revenue in 2014.
This year, the French chairman and CEO is joining US-based private-equity firm Catterton to form an investment firm with a consumer focus. The new firm, to be named L Catterton, is targeting $12 billion in assets under management and will be 40% owned by LVMH and Groupe Arnault.
(Photo by ERIC PIERMONT/AFP/Getty Images)
2. Charles Koch
Net worth: $46.8 billion
Industry: Diversified investments
Charles Koch is chairman and CEO of multifaceted conglomerate Koch Industries, the second-largest private company in America which their father founded. His younger brother David is the executive vice president. The company employs 100,000 people and generates $115 billion in sales from its diverse company, which makes everything from petrochemicals and Dixie Cups to raw clothing materials.
Outspoken in the world of conservative politics, the Koch brothers, who have a combined net worth of $94.2 billion, wield a heavy influence over the upcoming 2016 US presidential race. The two at one point favored Republican candidate and former HP CEO Carly Fiorina, but have since said that they won't support any of the current candidates in the primary. But they, along with their vast donor network, plan on pitching in some $750 million during the 2016 election cycle.
Recently surfaced documents revealed that Charles Koch's plans to reshape American politics date back 40 years, when he began strategizing and developing a libertarian movement.