One Month After the Coupang Incident, Beneficiary Stocks Return to Original Levels: "Long-Term Outlook Needed"

About a month has passed since the Coupang personal information leak incident, and the stock prices of companies previously considered beneficiaries have mostly returned to their original levels. This is interpreted as the result of limited user attrition, as Coupang’s dominant market position has prevented significant customer departures, thus limiting any potential benefits for competitors. However, the securities industry believes that if Coupang’s inadequate response leads to a prolonged decline in trust, the possibility of beneficiaries emerging remains open.

According to the Korea Exchange on December 29, Naver’s stock price fell by 5.12%, from 244,000 won on November 28-the day before Coupang announced the data breach-to 231,500 won on December 26. Meanwhile, Emart’s stock rose by 6.27%, from 78,200 won to 83,100 won, and CJ Logistics increased by only 3.4%, from 91,300 won to 94,400 won.

All of these companies were previously identified as potential beneficiaries of the Coupang data breach. Considering that the KOSPI index rose by 5.17% this month, their stock prices have barely changed. In particular, both Emart and CJ Logistics saw their stock prices climb as high as 94,300 won and 102,100 won, respectively, during the month, before trending downward.

On November 29, Coupang revealed that it had been under hacking attacks for about five months, from June to November, resulting in the leak of a total of 33.7 million customer account records. The leaked data reportedly included sensitive information such as names, emails, delivery addresses, order histories, and shared entrance passwords. Given that Coupang’s number of active users is about 24.7 million, this means that information equivalent to nearly half of the entire population was exposed.

Following the Coupang data breach, Naver, Emart, and CJ Logistics drew attention. Naver is strengthening its overall ecosystem lock-in through its Naver Plus Membership, which offers shopping, reservations, travel, and more. The structure provides Naver Points, free shipping, and online video streaming service (OTT) benefits simultaneously. Emart plans to launch a new membership program, “SSG Seven Club,” early next year, combining online shopping and content benefits. The new program goes beyond traditional discounts and delivery to include point accumulation and OTT partnerships. Similarly, expectations for CJ Logistics grew as demand leaving Coupang was expected to shift to its competitors and food companies’ own online malls, increasing logistics volume. With services like seven-day-a-week delivery and fresh delivery, CJ Logistics was already narrowing the service gap with Coupang, heightening market expectations.

However, the stock rallies were short-lived. This is because Coupang effectively maintains a monopolistic position in the e-commerce market. Despite the data breach, investors quickly concluded that actual user attrition would be limited.

Nevertheless, the securities industry is also paying attention to the possibility that this incident may not remain a short-term negative factor. As Coupang’s inadequate response continues, consumer and market trust are believed to be gradually eroding. Coupang emphasized that payment information and passwords were not leaked and only sent out precautionary text messages. However, there has been criticism that the follow-up measures were insufficient given the scale of the breach. Ultimately, the issue has expanded to a National Assembly hearing, the formation of a joint government task force, and a special tax investigation.

Recently, the announcement of investigation results has also sparked controversy. Coupang stated that it had identified the former employee responsible for leaking customer information and had retrieved and secured all devices and hard disk drives used to access and steal the data, with no evidence of external transmission. However, the announcement process has been marred by ongoing friction with government authorities.

Ultimately, this pattern of response is expected to undermine Coupang’s customer lock-in structure over the medium to long term. Nam Seonghyeon, a researcher at IBK Investment & Securities, stated, “The fundamental issue is being revealed in how Coupang is handling this situation. Due to Coupang’s inadequate response, the matter is becoming more serious, and over the medium to long term, we could see the departure of Coupang’s loyal customers and a decline in investor confidence.”