Coupang's stock soared 81% to open at $63.50. The company had priced 130 million shares sold in the IPO at $35 per share, higher than the marketing range $32-$34 per share, giving the Seoul-headquartered e-commerce giant a market value of $60 billion.

Founded in 2010 by Korean-American billionaire Bom Suk Kim, Coupang rose to prominence after launching its guaranteed same-day or next-day delivery service in the East Asian country. SoftBank's $100 billion Vision Fund owns 35.1% of Coupang.

Coupang's spectacular debut further bolsters the recent fortunes of the Vision Fund, which is bouncing back from an annual loss last March. Last month, it announced record quarterly profit.

Coupang operates an online marketplace that sells everything from fresh groceries to toys, as well as food delivery app Coupang Eats.

"We're laser focused on our home market," Kim said in an interview. "We're going to invest in 50,000 more jobs and billions of dollars more in not only the infrastructure, but the unique end to end technology that powers all of those services."

In 2020, Coupang's net sales jumped 91% year-on-year to $11 billion. Net losses narrowed to $567.6 million from $770.2 million posted in the prior year.

Coupang's successful share offering comes as the U.S. IPO market is at its strongest in more than two decades and investors are flocking to buy shares in technology companies that have benefited during the COVID-19 pandemic.

The IPO is the biggest in the United States this year, surpassing the $2.15 billion raised by dating app Bumble Inc. It also marks a jump in Coupang's valuation, which was pegged at $9 billion in a fundraising round in 2018, according to Pitchbook.

Analysts in South Korea said the strong response to Coupang's offering was a result of its market-leader position in the country at a time when, like many other e-commerce firms, its sales have grown due to the COVID-19 pandemic.

"Considering the high level of valuation inherent in the pricing, the market is giving a generous assessment of the company's achieving the top spot in market share," said Park Sang-joon, analyst at Kiwoom Securities.

Coupang was the top-ranked South Korean e-commerce firm in 2020 with 19.2% market share, according to Euromonitor, compared to Naver Corp's 13.6% and eBay Korea's 12.8%. It was the 10th largest e-commerce firm in the world, based on retail value excluding sales tax.

Goldman Sachs, Allen & Co, JPMorgan and Citigroup are the lead underwriters for the offering.

(Reporting by Chibuike Oguh and Krystal Hu in New York, Joshua Franklin in Boston, Joyce Lee, Heekyong Yang in Seoul, Noor Zainab Hussain and Niket Nishant in Bengaluru and Scott Murdoch in Hong Kong; Writing by Sumeet Chatterjee; Editing by Aurora Ellis, Stephen Coates, Gerry Doyle and Sriraj Kalluvila)

By Chibuike Oguh, Joshua Franklin and Joyce Lee