HONG KONG — As stock market stories go, the listing of Shenzhen Hepalink Pharmaceutical in China came with a few special ingredients: two low-key founders who have been turned into multibillionaires overnight; a stake held by Goldman Sachs; and pigs’ intestines.

On Thursday, in their first day of trade on the Shenzhen stock exchange, the shares of Shenzhen Hepalink, a heparin supplier, rose 18.3 percent above the offering price, valuing the company at about 70 billion renminbi ($10 billion). The initial value and the sharp rise on Thursday recalled the days before Lehman Brothers collapsed, and the gains bucked another weak session for Asian stock markets.

The listing has most likely catapulted the founders, Li Li and his wife, Tan Li, to the top of the list of China’s richest people; the two hold about 288 million shares of the company they founded in 1998, according to the state-run news agency Xinhua. At a closing price of 175.2 renminbi, their stake is worth about 50.5 billion renminbi ($7.4 billion).

This easily tops the estimated fortune of Wang Chuanfu, president and executive director of the BYD Company, which makes cars and rechargeable batteries. He had been China’s wealthiest man, with an estimated fortune of $5.1 billion, according to data compiled by Hurun Report, a research and publishing house based in Shanghai.