When SK hynix dropped its US subsidiary listing, its stock rose more than 4%, but Hyundai Motor and Doosan fell the same day. If subsidiary listings are blocked, who wins and who loses?

What the regulation targets: "selling the value of one company twice"

When a subsidiary is listed separately, parent company shareholders own its value only indirectly and must share the fruits of its growth with new shareholders. This is the so-called duplicate listing discount. The starting point of this debate was the backlash from parent company shareholders after LG Chem spun off its battery business and listed LG Energy Solution in 2020.

This year the government actually put the brakes on the practice.

• On July 6, the Financial Services Commission issued duplicate listing guidelines. When a listed parent lists a subsidiary in which it holds a stake of 20% or more, a duty to protect shareholders applies, and listing on an overseas exchange does not grant an exemption (BizWatch, Daum, 2026-07)
• At a parliamentary audit on October 19, FSS Governor Lee Chan-jin said of the Solidigm listing that "both the FSC and the FSS judge that it falls under duplicate listing" (MTN, 2026-10-19)
• Since the regulation, new listings have fallen 37% from the same period a year earlier, and only one company has entered the KOSPI (2026-10 report)

Winners: shareholders of cash-rich parents

For SK hynix, the cost of "removing the discount" is small

Reuters reported in late September that Solidigm's valuation was being floated at up to $150 billion, with a fundraising of $15 billion (cited by SBS Biz, 2026-09). Dropping the listing means not getting that $15 billion from outside. The market still reacted with +4.42% because hynix can manage without it. Its Q3 operating profit consensus is about 77 trillion won, and additional shareholder returns of more than 30 trillion won are being discussed. Since Solidigm's investment can be funded from the parent's cash flow, from a shareholder's perspective only the dilution risk has disappeared.

It is not free, however. A Solidigm IPO was also a way to expand SSD investment capacity and reduce the parent's need for further capital injections (News Tomato, 2026-10). Now that investment has to come out of hynix's cash, competing for the same money as shareholder returns. If shareholder returns fall short of expectations in the 10/28 earnings, the basis for this rebound weakens.

Losers: groups for which subsidiary listings were both a funding source and a stock catalyst

1. Groups that need funding

Money Today, covering cases of companies giving up listings and returning investment funds after the regulation, reported that "corporate funding lifelines have dried up" (Money Today, 2026-10-13). Unlike hynix, for groups without ample cash flow, subsidiary IPOs are a key source of growth investment. If this channel is blocked, the parent must fill the gap with borrowing or share issuance, and that burden ultimately falls on parent shareholders.

2. Parents whose share prices included expectations of a subsidiary listing

Boston Dynamics is the prime example. Some in the brokerage industry value it at more than 100 trillion won, but others point out that the value of the robotics business is already reflected in Hyundai Motor's share price, making a "double counting" controversy hard to avoid (Daum, Dealsite, 2026-07-08). If the listing is blocked, the opportunity to have that value confirmed by the market disappears. Hyundai Motor -1.99% and Doosan -4.46% on 10/23 can be read as the market discounting the possible loss of this "value realization event."

Governance adds another variable. Chairman Chung Euisun was reported to personally own about 22% of Boston Dynamics (2026-07), a structure in which a subsidiary listing pits the interests of the owner against those of parent shareholders. This is exactly what the regulation targets.

3. Shareholder activism opens the next front

Shareholder activism platform ACT, after derailing the listing of LS Group's Essex Solutions, named HD Hyundai Robotics as its next target (2026-07 report). A requirement for shareholder consent under a "3% rule" approach is also being discussed for listings of spun-off subsidiaries. The greater the bargaining power of minority shareholders, the harder subsidiary listings become.

Summary of the asymmetry

So what should investors do?

• Check two things when looking at a parent. First, can the parent's cash flow cover the subsidiary's investment? Second, how much of a subsidiary listing expectation is in the current share price? If the first is "yes" and the second is "little," the regulation is positive; if the reverse, it is negative
• SK hynix's benefit is only half confirmed. In the 10/28 earnings, check both the Solidigm investment plan and the scale of shareholder returns. If the two numbers conflict, the effect of removing the discount is halved
• For groups like Hyundai Motor, Doosan and LG Electronics that were considering overseas subsidiary listings, watch the disclosures. If a withdrawal is formalized, there will be near-term discount pressure; conversely, if a listing is allowed with shareholder protections attached (such as priority allotment to parent shareholders), it could actually be an opportunity for parent shareholders. Until the specifics of the protections come out, it is better to hold off on buying based on listing expectations