China’s world-best stock market rally made January the busiest month for IPOs in a year. It also created a bundle of new billionaires.

In the first six weeks of 2015, the world’s second-biggest economy hatched about two dozen billionaires, many of whom are riding initial public offerings that investors are driving to their daily price-trading limits -- a frenzy that harkens back to the IPO market of the late 1990s. Among the high-fliers are an airline, a video-game developer and a drug-store chain.

“IPOs have become very hot investment products in China,” said Ronald Wan, chief China adviser at Hong Kong-based Asian Capital Holdings Ltd., a Hong Kong-based corporate advisory firm. “So all the controlling IPO shareholders become very rich afterwards -- they become billionaires.”

After a 14-month standstill beginning in October 2012, IPOs resumed in China last year. More than 20 new stocks started trading in January, the most since the same month a year earlier. The offerings follow a 49 percent rise in the Shanghai Composite Index, the world’s best-performing index in 2014.

While the Shanghai index is little changed this year, the Shenzhen Composite Index, the smaller of China’s two stock exchanges, is up 13 percent in U.S. dollar terms, Asia’s highest returns and trailing just Russia and Saudi Arabia globally.

Shenzhen Rally

The Shenzhen rally has produced at least three new billionaires: Xiao Fen, whose electronics company, Shenzhen Fenda Technology Co., invested in a maker of Google Glass-like products; Ruan Hongxian, the chairman of Yunnan Hongxiang Yixintang Pharmaceutical Co., China’s third-biggest publicly traded drug-store chain; and Zhou Wei, chairman of medical software developer Shanghai Kingstar Winning Software Co.

In Shanghai, where gains in the first day of trading are capped at 44 percent and subsequent daily increases are limited to 10 percent, Wang Zhenghua, the 70-year-old chairman of Spring Airlines Co., landed a $1.3 billion fortune after the stock surged by the daily limit in the nine days after it trading debut.

Spring Air, whose executives share hotel rooms and eat instant noodles on business trips to keep costs down, has more than quadrupled in value since the IPO, with the company emerging as Asia’s biggest budget carrier by market capitalization.

‘Man-Made Scarcity’