The richest people on the planet got even richer in 2013, adding $524 billion to their collective net worth, according to the Bloomberg Billionaires Index, a daily ranking of the world’s 300 wealthiest individuals.

The aggregate net worth of the world’s top billionaires stood at $3.7 trillion at the market close on Dec. 31, according to the ranking. The biggest gains came in the technology industry, which soared 28 percent during the year. Of the 300 people who appeared on the final ranking of 2013, only 70 registered a net loss for the 12-month period.

“The rich will keep getting richer in 2014,” said John Catsimatidis, the billionaire founder of real estate and energy conglomerate Red Apple Group. “Interest rates will remain low, equity markets will keep rising, and the economy will grow at less than 2 percent.”

Bill Gates, the founder and chairman of Microsoft, was the year’s biggest gainer. The 58-year-old tycoon’s fortune increased by $15.8 billion to $78.5 billion, according to the index, as shares of Microsoft, the world’s largest software maker, rose 40 percent. Gates, who in May recaptured the title of world’s richest person, has also benefited from a rally in stock holdings that include the Canadian National Railway, which rose 34 percent, and a maker of sanitizing products, Ecolab, which rose 45 percent.

Less than a quarter of Gates’s fortune is held in Microsoft. Most of his assets are held in Cascade Investment, an entity through which he owns stakes in about three dozen publicly traded companies and several closely held businesses, including Four Seasons Hotels and Resorts and Corbis, a photo archive company. He has donated $28 billion to the Bill & Melinda Gates Foundation.

John Pinette, a spokesman for Gates, declined to comment.

Sheldon Adelson, founder of Las Vegas Sands, the world’s largest casino company, was the second-biggest gainer in 2013, adding $14.4 billion to his net worth as the company’s shares rose 71 percent. Gaming revenue from the six operators of China’s only legal casinos rose 18.6 percent to $45.2 billion last year, Macau’s Gaming Inspection and Coordination Bureau said.

Las Vegas Sands had revenue of $13.2 billion in the 12 months ending Sept. 30. More than 58 percent of its sales come from Macau.

Carlos Slim lost $1.4 billion during 2013. His America Movil, the largest mobile-phone operator in the Americas, dropped 12 percent in the first three months of the year after Mexico’s Congress passed a bill to quash the billionaire’s market dominance. The company finished the year up 2 percent after a planned expansion into Europe was reined in, reassuring investors who were leery about the billions of dollars in investment the strategy would require.

The 73-year-old Mexican is $51 billion ahead of Jorge Paulo Lemann, Latin America’s second-richest person and Brazil’s wealthiest. Lemann’s 3G Capital completed its $29 billion acquisition of Pittsburgh-based H.J. Heinz in June, a transaction done with Warren Buffett’s Berkshire Hathaway. With his two partners, the Brazilian billionaire, a former professional tennis player, manages three iconic American brands: Burger King, Budweiser beer and Heinz ketchup.

Nobody lost more of their fortune than Eike Batista, whose net worth declined more than $12 billion. OGX Petroleo & Gas Participacoes, the oil company that transformed him into Brazil’s richest man, filed for bankruptcy protection in October. Batista was the world’s eighth-richest person in March 2012 and now has a negative net worth, according to the Bloomberg ranking.

“His loss of credibility is explained by not delivering on the results promised when he listed his companies,” Elad Revi, an investment analyst at Spinelli, said by telephone in a July 26 interview from Sao Paulo. “There was a chain reaction — he lost credibility in one, then he lost it in all of them.”

Bloomberg News uncovered 109 billionaires in 2013 who have never appeared on an international wealth ranking, including Lynsi Torres, the youngest female U.S. billionaire. The 31-year-old heiress to In-N-Out Burger has watched her family expand the chain from a single drive-through hamburger stand founded in 1948 in Baldwin Park, Calif.

Stephen Orenstein, 50, made his fortune in more hostile environs. As the majority owner of Supreme Group BV, Orenstein has overseen the delivery of food and fuel to some of the most inhospitable parts of the world, including Liberia, Mali and Sudan. His biggest business has been supplying military personnel in Afghanistan, where contractors dodge bullets fired by the Taliban and explosives set by insurgents.

Shutterstock founder Jonathan Oringer rode a 222 percent surge in his company’s stock to become the first billionaire to emerge from Silicon Alley, a collection of technology start-ups in New York. The 39-year-old founded Shutterstock in 2003 with 30,000 of his own pictures and turned it into the world’s largest stock photo and video marketplace. He has net worth of $1.5 billion.

C. James “Jim” Koch popularized craft beer in the United States and transformed Boston Beer Co. into the second-largest American-owned brewery. It also made him a billionaire, as frothy sales of his flagship Samuel Adams brand helped Boston Beer stock rally 80 percent in the past year.

“What he has done is amazing,” said David Geary, president of D.L. Geary Brewing, a craft brewer in Portland, Maine. “He’s very focused, a brilliant marketer, and he sort of taught us all how to sell beer.”

Elon Musk’s net worth had the biggest percentage gain by a self-made billionaire, surging 233 percent during the year. Musk’s Tesla Motors, the electric-car maker being reviewed by U.S. regulators over battery-related fires, more than quadrupled, helping the billionaire add $5.6 billion to his fortune. Tesla’s Model S, with a $70,000 base price, kept its five-star rating, the highest designation given by the National Highway Traffic Safety Administration. The agency opened a review of the car in November after fires in Tennessee and Washington state occurred when drivers struck metal debris.

Mark Zuckerberg was technology’s biggest dollar gainer, adding $12.4 billion to his net worth as Facebook’s shares more than doubled. The chief executive of the world’s largest social-networking company sold more than $2 billion in stock last month and donated $1 billion to the Silicon Valley Community Foundation.

The fortunes of Larry Page and Sergey Brin, the founders of Google, surged about $10 billion each as the world’s largest search-engine business rose 58 percent.

“Google is very much investing,” said Eric Schmidt, the company’s chairman and the world’s 118th-richest person. “We’re hiring globally. We see strong growth with the arrival of the Internet everywhere.”

Carl Icahn spent much of the year jousting with other billionaires while adding $7 billion to his net worth. The 77-year-old financier battled with short-seller Bill Ackman over Herbalife and tried to snatch Dell from founder Michael Dell during his failed attempt to take the company private.

Henry Kravis’s fortune rose about $740 million this year. KKR, the private-equity firm he founded with his cousin George Roberts, said in December that it raised $1.5 billion for its first real estate fund, with most of the money to be spent in North America and as much as a quarter of it in western Europe.

“We think energy on a global basis is going to be very interesting for us,” Kravis said in a November interview. “And of course with the uncertainty in health care, that does create some opportunities for us.”

The outlook was less rosy for Steven A. Cohen, the founder of SAC Capital Advisors. While the company posted a 20 percent gain in 2013, according to a person briefed on the returns, the 57-year-old tycoon’s $14 billion hedge-fund firm struck a $1.8 billion deal in November to end a criminal investigation into insider trading. SAC agreed to pay the record fine and shutter its investment advisory business. Cohen will still manage his personal wealth, which is valued at $8.7 billion.

Li Ka-Shing remains Asia’s richest man, with a fortune of $30.2 billion. The 85-year-old controls the Cheung Kong Holdings property investment company and conglomerate Hutchison Whampoa.

The billionaire indicated in October he may sell stakes in Hutchison’s retail unit and Power Assets, Hong Kong’s second-largest power supplier, to free up capital to acquire more assets in Europe, where his companies have spent $14.5 billion on acquisitions the past three years.

The biggest gainer in Asia was Macau casino mogul Lui Che Woo, who added $14.2 billion to his net worth. Lui’s Hong Kong-listed Galaxy Entertainment has one of six gambling licenses in the Chinese enclave. Galaxy shares soared 129 percent in 2013 as Lui and his son Francis expanded their biggest property, Galaxy Macau, in the city’s Cotai area to capitalize on record visits by gamblers from China.

The title of China’s richest person changed hands twice during the year. Beverage billionaire Zong Qinghou was eclipsed in August by Dalian Wanda Group property and entertainment mogul Wang Jianlin after regulatory filings showed Wang’s non-real-estate businesses are more valuable than previously calculated.

Robin Li, founder of Beijing-based Baidu, dethroned Wang in December. China’s most-used search engine rallied 77 percent in 2013. But the crown could change again. The country’s top four billionaires all have fortunes of $12 billion or more.

Fast Retailing Chairman Tadashi Yanai, Japan’s richest man, ended the year with a $20.9 billion fortune, up 66 percent in 12 months. SoftBank President Masayoshi Son’s wealth more than doubled to $19 billion. SoftBank paid $22 billion to acquire telecommunication provider Sprint in July, topping a competing offer by Dish Network billionaire Charlie Ergen.

Amancio Ortega held on to his title as Europe’s richest person. Inditex, the world’s largest clothing retailer, rose 14 percent during the year. The billionaire reportedly bought an office building in London’s West End for $679 million.

Sergey Galitskiy, founder of OAO Magnit, Russia’s largest food retailer, added $5.3 billion to his net worth in 2013, more than any other Russian billionaire. The 46-year-old has a $13.8 billion fortune.

“Billionaires are asking what they should do with their money in 2014,” Mark Haefele, Global Head of Investment for UBS’s wealth management unit, said by phone from New York. “Central banks will continue to be supportive, so equities will likely continue to rise.”

— Bloomberg News