Chip Stocks and the AI Trade: Nvidia to SK hynix — 2026-09-26

Top developments

Samsung narrows HBM gap with SK hynix to 17 percentage points

Samsung Electronics' HBM4 production yields have stabilized into the "golden yield" zone of around 80%, up from below 60% in early mass production, giving confidence to expand supply. The HBM market share gap with SK hynix narrowed from 37 percentage points to 17 points, per Seoul Economic Daily reporting on September 21. This sets up a sharper Q3 battle between the two memory giants, with Korean analysts suggesting Samsung may have the edge on HBM4 pricing and margins.

SK hynix cements 50% HBM share, still leader on revenue

SK hynix recorded a 50% revenue-based share of the HBM market, cementing its lead even as Samsung's chase intensifies, per Global Economic citing The Motley Fool's September 23 report. Goldman Sachs meanwhile set a 3.5 million won price target on SK hynix, whose Seoul shares closed at 1.862 million won on September 23, up 1.2%.

Taiwan hits record 48,600+ intraday high; TSMC at NT$2,500

Taiwan's index surged on September 22 to a record intraday 48,601 points, closing up 1.14% at 47,719 on over NT$1 trillion in volume, with foreign investors buying NT$453.2 billion concentrated in ABF substrate makers, MediaTek and advanced packaging. The following day the index closed up 357.12 points at 48,157.29, with TSMC closing at NT$2,500, up 1.63%. Local buy-side houses flagged 15 advanced-packaging names as buys.

Tokyo chip stocks extend rally; SOX momentum drives Nikkei

On September 25, the Nikkei 225 rose for a fifth straight session, closing up 850 yen at 66,364, with Kioxia up as much as 3.04% and Advantest closing near highs at +2.84%. The prior week's SOX rebound (3% gain) fueled broad buying of Japanese equipment names including Advantest, Tokyo Electron and Laser tec. Japanese media also flagged Advantest's rebound on a reported Nvidia comment that sales could double next year.

Bernstein: Samsung's HBM growth outpaced SK hynix in August

Per Bernstein, Samsung's HBM growth outpaced SK hynix's in August, a data point reinforcing the Korean-language coverage that Samsung is closing in on its rival ahead of Q3 earnings.

Local view

Taiwan's United Daily News and TechNews emphasized foreign buying of the advanced-packaging "shovel" chain — ABF substrate trio, ASE Investment Control (5 straight days of foreign buys, 23,300 lots) andaths around TSMC's CoWoS franchise, with TrendForce cited by Commercial Times saying TSMC's CoWoS-L remains the mainstream advanced packaging choice through 2028 despite Intel's EMIB-T push.

In Korea, Chosun Biz reported Q3 operating profit consensus for both Samsung and SK hynix was revised sharply upward, framing HBM4 as the deciding factor.

Context & numbers

• TSMC's CoWoS-L advanced-packaging capacity is fully booked through 2026, and ~$22B in customer prepayments have locked memory supply — hyperscalers treating HBM access as structural.
• TSMC held roughly 72% of top-ten contract foundry revenue in Q1 2026 (TrendForce).
• SK hynix NASDAQ-listed shares (SKHY) fell 1.5% on September 24, trading at $186.37 on lighter volume (68% below average).
• Taiwan index closed 48,157.29 on September 23; volume NT$856 billion.

On the radar

• Q3 earnings season forSamsung and SK hynix in October — watch HBM4 revenue mix and DRAM contract pricing commentary.
• Advantest and Tokyo Electron results due September 29, per Nikkei, with focus on memory capex orders.
• Investor positioning: retail investors in Korea turned net sellers of Samsung/SK hynix this month after five months of buying (Chosun Biz, September 13) — a sentiment shift worth monitoring.
• Note: US BIS export-control research returned mostly January 2026 material; no fresh rule changes verified within the past week.