Why SK Group is chasing a 'quadruple listing' — and what Chey Tae-won stands to gain

SK hynix has found itself at the center of a debate over overlapping listings, as its US-based subsidiary Solidigm pursues a pre-IPO funding round. The market widely views the move as groundwork for a NASDAQ listing.

SK Group's official position is that it is "reviewing various options but has not finalized anything." In the language of corporate disclosure, that is not a denial.

SK Group already operates a triple-listing structure — SK Inc., SK Square and SK hynix. Adding Solidigm would create a quadruple-listing structure, the first of its kind in South Korea and rare even globally. SK is no stranger to the controversy: the initial public offering of SK On was previously delayed amid backlash over overlapping listings. So why is the group reaching for an option that could reignite the same debate?

Chey Tae-won's economic stake in semiconductors set to grow

The first thing to examine is why SK chose to create a subsidiary called Solidigm rather than listing NPS itself. Having transferred its core NAND flash research, development and sales operations to Solidigm, NPS has been repositioned as a vehicle for AI investment and related solutions businesses. SK hynix has also drawn up plans to invest up to $10 billion in NPS through 2030. The move reads as Chey's bid to pursue global AI-related investments in the mold of Nvidia's Jensen Huang or SoftBank's Masayoshi Son — making NPS, in effect, an AI investment holding company.

Beyond parent SK hynix, the group's holding company SK Inc., affiliate SK Telecom and SK Innovation will also invest in NPS — an ownership structure with no domestic precedent. Under South Korea's Fair Trade Act (Article 18), a holding company may not make equity investments in affiliates other than its own subsidiaries, and subsidiaries may not hold shares in companies other than their own sub-subsidiaries. But those restrictions apply only to domestic entities. Because NPS is incorporated overseas, the rules do not apply.

SK Group's decision — which exploits a gap in domestic law — also reshapes the economic relationship between Chey and NPS.

Along the current chain of Chey — SK Inc. — SK Square — SK hynix — NPS, Chey's indirect economic interest in NPS stands at roughly 1.15 percent. If SK Inc. invests $250 million in NPS, an additional roughly 0.4 percentage point of economic interest flows through that new channel. The paths of Chey — SK Inc. — SK Telecom — NPS and Chey — SK Inc. — SK Innovation — NPS would add approximately 0.32 percentage point and 0.13 percentage point, respectively. In simple terms, Chey's indirect economic stake in NPS would rise from roughly 1.15 percent to about 2 percent.

Under the new structure, Chey moves closer to the economic fruits of the semiconductor business — fruits that previously required passing through multiple layers of SK hynix. If that were the only goal, the restructuring alone would suffice. But a question remains: why does Solidigm need outside shareholders and a stock market listing at all?

Solidigm starts laying golden eggs — in step with SK hynix

Once Solidigm lists, the interests of NPS and incoming outside shareholders could diverge. The more equity outside investors take, the smaller the share of Solidigm's future profits that flows back to SK. If a listing is still being considered, there must be a compelling reason.

That reason becomes clearer when you look at Solidigm's financials. The business transferred to Solidigm was hammered by the NAND downturn in 2023, posting sales of 3.01 trillion won ($2.13 billion) and a net loss of 4.03 trillion won. By 2024, it had turned the corner, with sales of 8.85 trillion won and net profit of 830.7 billion won. In 2025, performance improved further, with sales of 9.18 trillion won and net profit of 1.39 trillion won.

The outlook for further improvement is strong.

According to research firm Gartner, the global NAND market is projected to expand roughly fivefold, from about $68 billion in 2025 to $341 billion in 2027, implying a compound annual growth rate of 123.7 percent. Over the same period, the HBM market is forecast to grow at 60.5 percent annually — meaning NAND is on track to grow more than twice as fast as HBM.

Within NAND, the outlook for eSSD — Solidigm's core product — is even brighter. In the AI era, the ability to design and optimize products for a customer's specific data center environment is becoming as important as producing large volumes of chips cheaply. SK hynix manufactures the NAND; Solidigm turns it into finished SSDs tailored to enterprise customers.

An eSSD is not simply a storage device that bundles multiple NAND chips together. It requires advanced error-correction capabilities, power-loss protection and high-performance controllers. Solidigm is well positioned to generate substantial added value throughout that process.

That is where the tension begins. Solidigm's shareholders benefit when NAND is purchased from SK hynix at a lower price; SK hynix's shareholders benefit when NAND is sold to Solidigm at a higher price. For now, the two are effectively one pocket — but the moment outside shareholders enter Solidigm, those interests diverge.

AI and cloud data centers plan their investments over multi-year horizons. If Solidigm builds a business model centered on long-term supply agreements, its earnings volatility could be significantly reduced. That makes it quite plausible that the market would assign Solidigm a higher valuation than SK hynix, a commodity chipmaker exposed to cyclical swings in capital expenditure and product pricing.

Consider a scenario in which the market values 1 trillion won of NAND profit at SK hynix at 5 trillion won, but values 1 trillion won of eSSD profit at Solidigm at 10 trillion won. The same 1 trillion won of profit, originating from the same NAND, could be worth 5 trillion won or 10 trillion won depending solely on which company's books it appears on.

Once Solidigm lists, this is no longer a simple matter of intercompany transactions. It becomes a question of how economic gains are divided between SK hynix shareholders and Solidigm shareholders — which ultimately comes down to how much of the value created between SK hynix and Solidigm is left in each company. And Solidigm sits closer to Chey than SK hynix does.

Could Solidigm be valued higher than SK hynix?

If the pre-IPO proceeds through a new share issuance, Solidigm could raise substantial investment capital from outside sources without drawing on funds from SK hynix or NPS.

What it gains could matter even more than the money. Bringing in major US hyperscalers or AI infrastructure companies as strategic investors would transform the relationship from a simple buy-and-sell arrangement into a tightly bound "invest–co-develop–long-term purchase" partnership. If global financial institutions come in as financial investors, they could become important funding partners for future AI data center investments and acquisitions.

Viewed from the perspective of SK Group as a whole, an even larger picture emerges. Outside of semiconductors and telecommunications, SK Group's business performance has been unimpressive, and much of its operations remain concentrated in South Korea. The group needs to find new growth engines beyond chips in the fast-expanding AI market and extend its reach internationally.

SK hynix plans to invest up to $10 billion in NPS, with additional capital coming from SK Inc., SK Telecom and SK Innovation. The structure positions NPS — with Solidigm as its cash-generating core — to serve as an investment platform within the US AI ecosystem.

If NPS's investments pay off, the next steps follow naturally. When an AI venture backed by NPS grows significantly, it could be spun off into a standalone company through an in-kind contribution or physical split, attracting outside capital in its own right. A second or third Solidigm could be built the same way. Listing Solidigm serves NPS's interests — and NPS's gains are also Chey's gains.

There is still no precedent for a major South Korean conglomerate directly listing an affiliate on a US exchange. In that sense, Solidigm's pre-IPO and potential NASDAQ listing may be more than just the flotation of a single subsidiary. It could be the first test of a new corporate and capital strategy for SK's expansion in the US AI market.

NASDAQ has no separate regulation prohibiting overlapping listings the way South Korea does, so the path is open if SK chooses to proceed. Success could redraw SK Group's governance map — and set a new benchmark for other Korean companies as well. That said, a rigorous process to verify that the structure does not disadvantage shareholders appears necessary. That, after all, is precisely why South Korea's Commercial Act was recently amended to establish directors' duty of loyalty to shareholders.