A Coupang fulfillment center in Bucheon, South Korea.
Hong Kong CNN Business  — 

Coupang, South Korea’s biggest e-commerce company, has pulled off the largest US initial public offering so far this year.

Shares of the SoftBank (SFTBF)-backed firm ended their first day of trading on the New York Stock Exchange at $49.25 on Thursday, a 41% jump over the $35 IPO price.

The offering raised nearly $4.6 billion. The first day spike gives the company a market capitalization of $84.5 billion.

The offering surpasses dating app Bumble’s Wall Street IPO, which raised more than $2 billion last month. It’s also one of the biggest listings ever by an Asian company on a US exchange, according to Dealogic.

Coupang, which is based in Seoul, is South Korea’s answer to Amazon (AMZN). It was founded in 2010 by Bom Kim, who studied at Harvard University, and has since expanded its footprint to Silicon Valley, Shanghai and Seattle.

Kim is personally now worth about $8.6 billion after taking his company public, according to the Bloomberg Billionaires index.

Coupang is popular for its “rocket delivery” service, which promises customers free shipping within hours, or the next day. But the company has also faced some criticism in South Korea over working conditions, which local media have linked with the deaths of two of its delivery workers.

Coupang has previously said that it was notified by authorities in South Korea that the death of Jang Deok-jun, who worked at one of its logistics centers, “was ruled to be a work-related illness.”

“We give our condolences and apology for Mr. Jang. We offer our deep condolences to his family to and we will actively seek to support his family,” the company said in a statement last month. “We will put together the reforms that we had been preparing … and do our best to create the environment where workers can work safely,” it added.

In a separate statement Thursday, Coupang said it expressed “deep condolences” to the family of the second worker, who passed in early March. He was not identified.

The company said the employee had logged 40 hours a week, significantly less than the typical work week of most delivery workers. It urged the media to refrain from reporting speculation surrounding the death, or unconfirmed claims.

“The authorities are working to uncover the exact cause of death and the company is doing its best to cooperate,” it said. “[We] will not spare any support in reducing the pain felt by the deceased’s family.”

Like many e-commerce companies, Coupang’s business has grown during the coronavirus pandemic as more people stay home and shop online. When the crisis first started, the company’s next-day delivery orders jumped from just over 2 million to 3.3 million per day.

“We saw a surge in demand across all categories,” Kim told CNN in an interview last April.

Coupang lost about $475 million in 2020, an improvement on the $699 million net loss recorded the previous year, according to an SEC filing. But it has managed to impress investors.

“Coupang is potentially setting a new benchmark for global e-commerce companies across Asia and the US and there are a number of key lessons startups can learn from what Coupang has achieved,” according to Goodwater Capital, a California venture capital firm that has previously invested in the startup.

The company’s customer loyalty and dominance in South Korea suggest that “in some ways, [it’s] out-Amazoning even Amazon,” the firm wrote in a report Wednesday.

“A lot has to do with their innovations on the delivery model,” said Goodwater Capital managing partner Eric Kim, a former Coupang board member.

“They have something called dawn delivery. If you order at midnight, you can get it at 7 am,” he told CNN Business.

Interest in the IPO, meanwhile, has been hot. Previously, the company had said that it would sell shares for somewhere between $27 and $30 each before hiking that range to $32 to $34 — and then finally pricing at $35. It also raised the number of shares it planned to offer, from 120 million to 130 million, including some from existing shareholders.

The buzz comes at a good time for SoftBank, Coupang’s biggest shareholder. The Japanese conglomerate has invested at least $3 billion in Coupang since 2015, and its Vision Fund owns over 35% of the company. Its stake is now worth close to $30 billion.

While tech stocks have experienced some volatility in recent weeks, they have generally been on an incredible run over the past year. SoftBank CEO Masayoshi Son has seized on the rally and called on his portfolio companies to go public, suggesting that they could help his fund lay “golden eggs.”

— CNN’s Selina Wang and Jake Kwon contributed to this report.