Why are Micron and SK Hynix stocks struggling today? It's the CXMT threat again

Memory stocks were falling on Thursday even as Wall Street's broader indices climbed, after fresh data showed that China's leading memory chipmaker had more than doubled its share of the global DRAM market in the space of a year.

Micron Technology MU fell about 2.3% and South Korea's SK Hynix declined 4% on the day, when the S&P 500 gained 0.4% and the Nasdaq was up approximately 0.8%.

At the time of writing, both stocks had regained some losses, with Micron down by 0.8% and SK Hynix down by 2%.

The trigger was a Counterpoint Research report showing that ChangXin Memory Technologies, known as CXMT, had captured 10% of the global DRAM market in the second quarter of 2026, up from 4% during the same period a year earlier and from 8% in the first quarter — a pace of share gain that few analysts had modelled.

The Counterpoint data laid out a striking redistribution of the global DRAM market.

SK Hynix bore the sharpest decline, with its share falling from 39% in Q2 2025 to 25% in Q2 2026.

Samsung, by contrast, held the largest market share at 38%, up from 33% a year earlier.

Micron showed a more modest improvement, moving from 22% to 24% over the same period.

The overall DRAM market itself is expanding at extraordinary speed.

The Counterpoint report noted growth of 57% compared with the previous quarter and 385% compared with the same period a year earlier — a reflection of the insatiable demand for memory from AI data centres, which are consuming conventional DRAM for CPU workloads while simultaneously accelerating the uptake of next-generation high-bandwidth memory in GPU-intensive AI systems.

In the high-bandwidth memory segment — the most strategically critical corner of the memory market for AI applications — the picture was more nuanced.

SK Hynix retained the largest share at 50%, though that was down from 64% a year earlier.

Samsung more than doubled its HBM share from 15% to 33%, with Counterpoint noting that Samsung is expected to gradually increase its position further with the ramp of HBM4 shipments in the second half of the year.

Micron's HBM share fell to 18% from 21% in Q2 2025 — the first decline after holding a 21% market share across three quarters since last year.

CXMT enters the HBM conversation

What made Thursday's selloff more acute than a straightforward market share story was a separate report by The Information, published earlier in the week, disclosing that CXMT has begun producing advanced high-bandwidth memory in small quantities.

The company plans to expand that production in 2027, with Alibaba's T-Head semiconductor unit and Chinese AI chip designer Cambricon already testing CXMT's HBM with their processors.

If testing proceeds as planned, both companies could incorporate CXMT's HBM into products as early as next year.

The development adds a new dimension to a threat that markets have been tracking since CXMT's blockbuster IPO raised 57.92 billion yuan — approximately $8.6 billion — in Asia's largest initial public offering of the year, briefly making it China's most valuable onshore-listed company with a market capitalisation approaching $487 billion.

Despite becoming the world's fourth-largest DRAM maker, CXMT remains behind the three established leaders in advanced memory technologies, but its progress has unsettled investors already sensitive to any sign of Chinese competitive encroachment.

Reports that Apple was testing CXMT memory chips to manage a memory scarcity that forced it to raise prices across several Mac and iPad products have added further nervousness in recent months.

A subsequent report that Washington may permit Apple to source memory chips from Chinese suppliers including CXMT sent memory stocks lower again last month— a pattern that has become familiar in recent months as CXMT demonstrates that it can generate headline risk even before it has generated meaningful revenue from advanced products.

Analysts urge perspective on the CXMT threat

Not everyone is persuaded that the headlines reflect the underlying competitive reality.

KC Rajkumar of Lynx Equity Research has argued that supply constraints and qualification gaps make the China memory threat far smaller than the headlines imply.

His channel checks found CXMT qualified for only one low-volume Mac product and not qualified for iPhones at all, with poor yield on the high-density LPDDR5x DRAM Apple requires.

"CXMT supply is unlikely to dent the shortage Apple is facing in DRAM, nor could CXMT supply improve Apple's negotiation position at traditional suppliers such as Micron," Rajkumar wrote last month.

Ellie Wang, an analyst at TrendForce, told CNBC earlier that while CXMT continues to strengthen its domestic position, its capabilities remain relatively limited in high-capacity server memory and advanced products designed for AI servers.

That leaves global leaders including Micron, Samsung, and SK Hynix with a substantial advantage in supplying the rapidly expanding AI infrastructure market, even as Chinese manufacturers continue to build capacity and narrow the gap in conventional memory products.

The longer-term question CXMT is forcing the market to ask

Counterpoint Research Vice President Neil Shah offered the most considered long-term framing of CXMT's trajectory.

"An important thing to watch out for in H2 2026 would be how CXMT leverages its recent IPO to boost its prospects in terms of capacity expansion for HBM and LPDDR6," Shah said.

"If CXMT can expand its capacity and capability to meet domestic and overseas demand, starting with PCs and potential Tier-1 international customers, the supplier's market share will balloon and look a lot different a year from now. The question is not about 'how' but 'when' CXMT will be able to break into the Big Three Memory Club."

On Micron specifically, Shah remained constructive despite the quarterly share dip.

"According to our estimates, Micron's DRAM revenue has increased fivefold since Q2 2025, positioning the company to surpass SK Hynix and likely claim the second spot soon. Micron has normally been quite conservative and modest about this, but we believe the competition is strong and it will all boil down to who has enough capacity to not leave money on the table for others to grab and how the long-term agreements shape up," he said.

That last point may be the most important for investors trying to calibrate Thursday's selloff.

The structural demand for advanced AI memory remains intact and is expanding faster than any single supplier — including CXMT — can address.

The battle for market share is intensifying, but the market itself is growing fast enough that the established leaders can lose ground in percentage terms while simultaneously generating record revenue in absolute terms.