China’s export controls on Japan create bottlenecks; “White-Haired Stock God” Serenity says South Korean stock Foosung will become the “big winner”
TechFlow Selected TechFlow Selected
China’s export controls on Japan create bottlenecks; “White-Haired Stock God” Serenity says South Korean stock Foosung will become the “big winner”
South Korea’s replacement window is propped up by geopolitics, not technological barriers.
Navigating Web3 tides with focused insightsAuthor: Ada, TechFlow
The ripple effects of China’s tungsten export controls targeting Japan have now reached the upstream of AI memory chips.
Japan accounts for approximately 25% of global WF6 (tungsten hexafluoride) production capacity—and that capacity is now entering a countdown to shutdown. Samsung and SK Hynix have been forced to urgently seek alternative suppliers overnight. South Korea’s SK Specialty has signed a long-term supply agreement with Samsung for 150 tons per month; Foosung has initiated certification with China’s CSSC Specialty Gases (China Shipbuilding Industry Corporation Specialty Gases), aiming to begin large-scale imports starting in August. The 2026 contract price for WF6 has already been locked in at an increase of 70–90%; Japanese suppliers warn critical inventory may be fully depleted by mid-2026. On social media platform X, “White-Haired Stock God” Serenity singled out Foosung as a “major winner”—yet the inherent risks of this substitution game are equally clear: Korean producers themselves rely on imported tungsten powder to manufacture WF6.
Japan’s two leading WF6 suppliers—Kanto Denka Kogyo and Central Glass—have notified Korean customers including Samsung, SK Hynix, and DB HiTek that they cannot guarantee supply beyond May–June. This constitutes a major blow to downstream memory chips—the first direct impact transmitted from China’s export controls on tungsten-related items, which took effect in February 2025.
Ripple Effects of China’s APT Export Controls: Japanese WF6 Capacity Under First Pressure
As early as February 2025, China’s Ministry of Commerce and General Administration of Customs jointly announced the formal inclusion of tungsten-related items—including APT (ammonium paratungstate, a precursor to tungsten powder)—into the dual-use items export control list. The full impact of this move has only now crystallized over a year later. According to industry analyst CTOL Digital, since the controls took effect, Japan’s imports of APT from China along key trade routes have plunged by up to 70%—a stark figure directly choking Japan’s WF6 producers.
The pressure mounted faster than industry expected. As reported by Korean semiconductor media The Elec on April 3—citing multiple industry insiders—Kanto Denka and Central Glass have begun informing Korean chipmakers such as Samsung and DB HiTek that potential supply disruptions are imminent. One insider told The Elec: “Supply can be maintained through May and June using existing tungsten inventory, but the outlook for the second half remains uncertain.” Japanese manufacturers have advised their Korean customers to shift toward domestic alternatives—SK Specialty and Foosung.
Japan supplies roughly 25% of the world’s WF6. If Japanese producers cut output, one-quarter of the global supply of tungsten film material vanishes instantly. According to market intelligence firm SunSirs, Samsung and SK Hynix historically sourced about 80% of their WF6 from Japan—placing them squarely at the epicenter of this crisis. Among them, Samsung faces significantly higher exposure than SK Hynix, whose supply portfolio is more diversified—encompassing SK Specialty, Foosung, and China’s Peric Special Gases.
SK Specialty Signs 150-Ton/Month Long-Term Contract with Samsung; Top Korean Producers Rush Expansion
Faced with crisis, Korean manufacturers demonstrated exceptional execution speed. According to SunSirs, SK Specialty has signed a long-term supply agreement with Samsung for 150 tons per month—a volume highly unusual under normal conditions, given that WF6 is an ultra-high-purity specialty gas—not a commodity easily scaled up.
SK Specialty is Korea’s largest WF6 supplier and enjoys natural group-level synergy with downstream customers. It operates under the SK Group umbrella—already closely aligned with fellow SK Group affiliate SK Hynix—and has now extended its long-term agreement to include Samsung, effectively securing positions at both of Korea’s top memory manufacturers.
Time is the scarcest resource in this scramble for supply. WF6 is an extremely corrosive, hazardous gas requiring purity levels of 5N to 6N. New supplier qualification typically takes 12–18 months, covering process testing, yield validation, equipment compatibility, and more. Yet according to The Elec, some foundries are “shortening or skipping certain steps”—solely due to urgency.
Foosung Launches Certification with CSSC Specialty Gases, Targeting Large-Scale Imports from August
Foosung (Korean stock code: 093370) is pursuing a different path. This Korean fluorine chemical manufacturer—valued at approximately $1.2 billion—is one of SK Hynix’s three current WF6 suppliers, alongside SK Specialty and China’s Peric. Beyond WF6, Foosung is Korea’s sole producer of anhydrous hydrogen fluoride (HF), Korea’s second-largest WF6 manufacturer, and Korea’s only producer of lithium hexafluorophosphate (LiPF6), a battery electrolyte salt. All three fluorine chemical production lines operate within the same Ulsan facility—reflecting highly concentrated technical assets.
According to reports from SunSirs, Futunn, and other outlets citing industry sources, Foosung has initiated the qualification process with CSSC Specialty Gases (a subsidiary of China Shipbuilding Industry Corporation), targeting large-scale WF6 imports beginning in August. The underlying implication merits unpacking: Japan’s WF6 production has halted due to tungsten powder shortages; Foosung, instead of producing domestically, is importing finished WF6 from China. Thus, the same tungsten supply chain has been severed by China’s export controls into two distinct segments—one that “chokes Japan,” and another that “opens access for Korea.”
“White-Haired Stock God” Serenity on X has already taken note. In a post on June 13, he highlighted Foosung: “Foosung looks set to become a massive beneficiary. Essentially, China’s export controls on Japan have caused Japan’s WF6 supply chain to collapse—and the ~25% of global supply required by SK Hynix, Samsung, and TSMC must now be sourced elsewhere.”
The secondary market has already begun pricing in this logic. According to CTOL Digital, Foosung’s share price has surged approximately 196% over the past 12 months—even though its trailing-twelve-month (TTM) EPS remains negative.
2026 WF6 Contract Prices to Rise 70–90%; Japanese Suppliers Warn Inventory to Hit Bottom by Mid-2026
Price signals at the contract level have already emerged. According to CTOL Digital, Korean suppliers SK Specialty and Foosung, together with Japanese supplier Kanto Denka, have formally notified Samsung, SK Hynix, DB HiTek, and Magnachip that 2026 WF6 contract prices will rise 70–90%. This reflects collective pricing behavior within an oligopolistic market—where downstream buyers possess virtually no viable alternatives.
An even more alarming signal comes from the supply side. Per CTOL Digital, Japanese suppliers warn that critical inventory may be fully exhausted by mid-2026—meaning even Korean customers with long-term contracts face uncertainty regarding physical delivery.
WF6’s irreplaceability is being re-priced by the market. Chipmakers cannot freely switch between cylinders from different suppliers; any impurity deviation could scrap millions of dollars’ worth of wafers. This is precisely why new supplier qualification demands 12–18 months of rigorous testing—and why oligopoly structures persist in this sector.
Equity market reactions have already moved ahead of fundamentals. According to CTOL Digital, Japan’s Kanto Denka saw its share price rise ~374% over the past year, pushing its market cap to ¥240.3 billion, with a TTM P/E ratio exceeding 63x. Foosung rose ~196% over the same period—even though its TTM EPS remains negative—indicating significant market premium. These valuations reflect not short-term event-driven spikes, but a structural market reassessment of the WF6 oligopoly.
Korea’s Supply-Filling Window Is Geopolitically Enabled—Not Technologically Determined
The Korean manufacturers benefiting from Japan’s supply disruption are not fully self-sufficient. SK Specialty and Foosung—despite being domestic WF6 producers—still depend on imported tungsten powder to make WF6. So far, however, they have been treated differently from their Japanese peers. SunSirs notes: “China’s export controls thus far have primarily targeted Japan; Korea remains permitted to import tungsten powder—a geopolitical choice, not a natural outcome of market forces.”
China’s domestic supply side is rapidly rising. According to Futunn, citing industry data, CSSC Specialty Gases will reach 2,000 tons/year of WF6 capacity by end-2025, with 6N-grade purity—and its products have already entered the global semiconductor supply chain. SunSirs further reports that China’s domestic penetration rate for fluorinated specialty gases has risen sharply to 50% over the past two years.
This reality adds a clear footnote to Foosung’s “winner” narrative. The current window hinges entirely on the premise that “China continues permitting tungsten powder imports into Korea”—not on insurmountable technological barriers. Samsung and SK Hynix’s decision-makers may already be asking themselves the question SunSirs posed: “If Japan can be shut down due to raw material shortages, what, then, prevents Korea from facing the same fate tomorrow?”
Join TechFlow official community to stay tuned
Telegram:https://t.me/TechFlowDaily
X (Twitter):https://x.com/TechFlowPost
X (Twitter) EN:https://x.com/BlockFlow_News
深潮TechFlow
