At this summer's Olympics, Michael Phelps scored in the pool, Usain Bolt on the track and Ma Huateng at the bank.

Huateng is the founder of Tencent and is a Chinese Web titan. Big multinational companies, eager to make a good impression with the local audiences during the Olympics, snapped up advertising spots on Tencent's instant messenger, blogging and portal services. Earlier this month, Tencent said its quarterly earnings nearly doubled from a year ago.

In Pictures: Asia's Youngest Billionaires

This is good news for Tencent and for Huateng, since he owns a huge chunk of his company's stock. In March, Forbes estimated that the 36-year-old Web mogul is worth $1.4 billion.

Huateng is one member in Asia's exclusive group of the young and extremely affluent. These 15 billionaires, all under the age of 40, are worth a staggering $31.3 billion combined.

Huateng is neither the wealthiest nor the youngest in the club. When we published our list of the world’s billionaires in March, both superlatives went to Yang Huiyan, a 26-year-old with a net worth of $7.4 billion. Yang, a graduate of Ohio State University, joined the family real estate company, Country Garden Holdings, in 2005. The next year she received a hefty chunk of shares that are worth billions of dollars today.

The stock came from her father, Yeung Kwok Keung, who co-founded Country Garden. Don't question his wisdom of giving so much money and responsibility to a recent college grad: Yeung knows the value of a yuan.

Growing up in an impoverished Chinese village, Yeung reportedly never wore new clothes before he was 17. He raised cattle and then worked as a bricklayer and contractor, which led him to build houses and work in real estate. (See "China's Richest, Thanks To An IPO And Dad.")

Huateng and Yang are two of China's eight billionaires under the age of 40. Others include Xian Yang, a 34-year-old coal magnate, and Zhang Cheng Fei, a 38-year-old paper baron.

Youth and exceptional wealth are a rare combination, but this fortunate group will likely grow in Asia in the coming years. The region is home to the world's fastest growing population of the wealthy. According to the World Wealth Report, the population of China's millionaires jumped 20% last year. The billionaire population grew even faster. The March Forbes' list included 42 Chinese billionaires, up from 20 the previous year.

Keeping pace in the money race is India. The country's millionaires jumped 23% last year. The billionaire count soared to 53 from 36 the previous year.

That group counts six members that are under 40, like Anurag Dikshit. The engineer started PartyGaming, which owns PartyPoker.com, with a college roommate and former porn entrepreneur. Dikshit spearheaded the development of technology that helped launch the online poker boom. "All our technology is proprietary, and most of it is Anurag," a PartyGaming spokesperson once said. (See "PartyGaming's Billionaire Dikshit Quits Board.")

PartyPoker stock is off its 2005 high since U.S. lawmakers cracked down on online gaming, but Dikshit still has plenty of chips. Forbes pegs his net worth at $1.6 billion.

Also representing India is a pair of brothers, Malvinder and Shivinder Singh. The two have plenty in common: They went to the same schools in India, attended business school at Duke and started families just months apart. They're also both billionaires.

The two control Ranbaxy Laboratories, a drug company founded by their grandfather. It won't be the family much longer though. In June, a Japanese pharmaceutical company announced it would buy the Singh family's stake for about $4 billion. Not bad for a couple of guys in their 30s.

In Pictures: Asia's Youngest Billionaires