What Happened
Markets & Semiconductors · Taiwan · South Korea · China · Investment · Deep BriefSession of 28 Jul 2026
Asia-wide chip sell-off · one-session brief
Korea took the damage. Taiwan took the spillover.
On 28 July 2026 the TAIEX closed 2,030.83 points lower at 41,603.36 — its third-largest closing point drop on record. Measured as a percentage it was the mildest fall of Asia's three chip-exposed markets that day: South Korea's KOSPI, where the sell-off started, fell 10.84% and triggered a market-wide circuit breaker.
The Session in Four Numbers close · percentage · rank
- 41,603.36TAIEX close, −2,030.83 pts
- −4.65%Taiwan's decline — the mildest of the three
- −10.84%KOSPI, into a circuit breaker
- >13%Samsung and SK Hynix, both at the close
What's Confirmed, Graded exchange data first, narrative second
| Standing | What | Detail |
|---|---|---|
| Confirmed | That the TAIEX closed down 2,030.83 points (−4.65%) at 41,603.36, its third-largest closing point drop on record | Taiwan Stock Exchange historical index levels: 43,634.19 → 41,603.36. The two larger drops it trails are 17 Jul 2026 (−2,953.71) and 7 Apr 2025 (−2,065.87) |
| Confirmed | That KOSPI closed down 10.84% at 6,023.66, having triggered a 20-minute, market-wide circuit breaker at 10:13 a.m. local time | |
| Confirmed | That Samsung Electronics and SK Hynix both closed down more than 13% | At the moment the circuit breaker triggered, Samsung stood at −9.45% and SK Hynix at −11.01%; both fell further before the close, which is where the >13% figure comes from |
| Confirmed | That every Taiwan-listed stock most exposed to memory chips closed at the daily 10% limit | Winbond, Nanya Technology, Macronix and Powerchip (the memory names) and MediaTek, Delta Electronics, Yageo and UMC all closed at limit-down, per the exchange's own closing-quote table |
| Confirmed, not independently re-derived here | That CXMT's Shanghai debut closed roughly 466% above its offer price, briefly making it China's most valuable listed company | Figures from a single outlet's own reporting; a second, independent pricing source for the exact closing gain was not reached |
Three Sessions, Ranked by Points the same three the ranking claim rests on
| Date | Points lost | Close | Change |
|---|---|---|---|
| 17 Jul 2026 | −2,953.71 | 42,671.27 | −6.47% |
| 7 Apr 2025 | −2,065.87 | 19,232.35 | −9.70% |
| 28 Jul 2026 | −2,030.83 | 41,603.36 | −4.65% |
Ranked by points lost. By percentage the order reverses: 7 April 2025 was the deepest of the three and 28 July 2026 the shallowest — a fact about how much higher the index now stands, not about how severely the three sessions actually compared.
Timeline
Five Weeks to One Session 23 Jun to 29 Jul 2026
- 23 Jun 2026An earlier KOSPI crash: Samsung Electronics and SK Hynix both fall more than 12% a day after SK Hynix briefly overtook Samsung's market capitalisation for the first time since 2000; Korea's circuit breaker triggers twice.
- 24 Jun 2026SK Hynix's strategy shift is reported: the company is slowing its ramp of sixth-generation HBM4 memory to redirect capacity into conventional DDR5 DRAM, where a shortage it helped create had pushed contract prices up 90–95% quarter-on-quarter in the first quarter of 2026, per TrendForce.
- 17 Jul 2026The TAIEX's largest-ever single-session point drop: −2,953.71 points to 42,671.27.
- 27 Jul 2026 (Mon)ChangXin Memory Technologies (CXMT) debuts on Shanghai's STAR Market and closes roughly 466% above its offer price, briefly China's most valuable listed company; Nvidia's own shares fall roughly 4% in New York on renewed “circular financing” concerns about AI infrastructure spending.
- 28 Jul 2026 (Tue)The TAIEX closes −2,030.83 (−4.65%) at 41,603.36; KOSPI closes −10.84% at 6,023.66 after a 20-minute circuit-breaker halt; Samsung Electronics and SK Hynix both close down more than 13%.
- 29 Jul 2026 (Wed)KOSPI falls a further 5.98% to close at 5,663.24, a second consecutive circuit-breaker session; South Korea's finance minister tells lawmakers that the introduction of leveraged single-stock ETFs “had not been considered carefully enough.”
The Argument
Why Memory, Specifically a crowded trade, unwinding at once
Three strands landed on the same session. Scepticism about the return on AI capital spending had already been building — sharpened the week before by Alphabet raising its own capex outlook — and it showed up directly in Nvidia's shares, which fell roughly 4% in New York on 27 July on renewed “circular financing” concerns. Chinese memory competition became concrete the same day: ChangXin Memory Technologies' Shanghai debut closed up roughly 466%, and at least two bipartisan members of the US House of Representatives called for blocking American purchases of its chips within a day of the listing. And the structural strand runs back to 24 June: SK Hynix's own reported decision to slow its HBM4 ramp and redirect capacity into commodity DDR5 — a market its AI-driven HBM build-out had itself pushed into shortage, with DDR5 contract prices up 90–95% quarter-on-quarter in the first quarter of 2026, per TrendForce — is what left Korea's two dominant listings, Samsung and SK Hynix, sitting on a single commodity-memory cycle rather than a diversified book. Mega International Investment Services analyst Alex Huang, quoted by Focus Taiwan, put it plainly: “Even worse was that memory chip suppliers in South Korea tumbled this morning, triggering more of a sell-off among local semiconductor stocks.” He added that “market sentiment was badly hurt by fears that large AI investments by cloud service providers will not generate adequate sales,” and that thin turnover showed “many investors were reluctant to buy on the dip, fearing more volatility.” Frank Benzimra, head of Asia equity strategy at Societe Generale, named the mechanism behind the size of the move: “If you look at what is falling in the market, it has been the stocks in which you have the most leverage.”
- +466%CXMT's Shanghai debut, offer price to close
- −4%Nvidia's own shares, 27 July in New York
- 90–95%DDR5 contract-price rise, quarter-on-quarter, Q1 2026
What Others Add
Where the Damage Landed, Sector by Sector Taiwan Stock Exchange's own sub-indices, 28 Jul 2026
| Sector index | Move | Reading |
|---|---|---|
| Electronic components | −8.99% | The hardest hit of any sub-index — harder even than the plastics index below |
| Plastics | −8.30% | A traditional-industry sector, not a chip name — and harder hit than the semiconductor index itself; no published account explains why |
| Glass and ceramics | −7.95% | Third-hardest hit; also a traditional-industry sector |
| Electronics industry | −5.11% | The broad electronics group, dragged by its memory and components sub-sectors |
| Semiconductors | −4.42% | Milder than the broad electronics group — TSMC's own weight in this sub-index cushions it |
| Financials | −1.92% | The mildest of the major sub-indices |
| Index excluding electronics | −2.73% | With electronics removed, the rest of the market fell at barely half the headline rate — the session's damage was concentrated, not broad |
Turnover and Flow who traded, and how much
- NT$809.48bnTaiwan Stock Exchange turnover (~US$25.04bn)
- NT$87.56bnForeign institutional investors' net selling
- 96 / 931Stocks closing higher / lower, Taiwan main board
- ~$270bnCombined value erased from Samsung and SK Hynix over the two-session Korean rout
Three Markets, One Trade epicentre · spillover · entrant
Epicentre · South Korea
KOSPI −10.84%
- Korea Exchange triggered a market-wide circuit breaker at 10:13 a.m. local time, halting trading for 20 minutes.
- Samsung Electronics and SK Hynix both closed down more than 13%, the session's two worst-hit large caps.
- The rout continued the next day: a further −5.98% on 29 July, a second consecutive circuit-breaker session.
Spillover · Taiwan
TAIEX −4.65%
- TSMC alone closed −2.98% at NT$2,280.00, contributing roughly 560 of the index's 2,030.83 lost points.
- Taiwan's own memory names — Winbond, Nanya Technology, Macronix, Powerchip — closed at the 10% daily limit, as followers of Korea's move rather than its cause.
- Not every sector followed the chip story: Chunghwa Telecom and Taiwan Mobile both closed higher, and China Airlines and EVA Airways gained on defensive rotation.
Entrant · China
CXMT +466%
- ChangXin Memory Technologies' Shanghai debut was Asia's largest IPO of 2026 and the largest semiconductor listing in STAR Market history.
- A senior US federal official told the New York Post there was “a real suspicion” that state intervention played a role in the price action.
- At least two bipartisan members of the US House of Representatives called for blocking American purchases of CXMT's chips entirely.
Conclusion
So What what to hold, and what to hold loosely
Bottom line
A crowded AI-memory trade unwound across Asia on 28 July 2026. The damage concentrated exactly where AI-demand assumptions had done the most valuation work — Korea's two dominant memory names — and was mildest where cash flow is present-tense: Taiwan's telecom incumbents closed flat to higher even as its memory-adjacent stocks hit their daily limit. “Third-largest point drop in history” is a true statement about the TAIEX's own arithmetic, not a claim that 28 July was Asia's worst day: by percentage it was the mildest of the three markets that session, and milder even than the TAIEX's own 7 April 2025 fall.
The unexplained figure
Taiwan's plastics sub-index fell 8.30% — harder than semiconductors (−4.42%) and harder than the electronics industry index (−5.11%). No published account explains why a traditional-industry sector led a session everyone agrees was about chips. It stands as an open question, not folded into the memory-rout narrative.
What Would Actually Settle It structure, not sentiment
- Korean memory names stabilising — the causal upstream. Taiwan's memory names are followers here, not leaders, so a Korean stabilisation is the signal to watch first.
- Whether hyperscaler earnings support the AI-spending case — the results still due that week from Meta, Microsoft and Amazon are what will confirm or undercut the return-on-spend scepticism that helped trigger this session.
- Whether CXMT's valuation holds — a debut this size staying at a fraction of its first-day gain would ease the Chinese-competition strand of this trade; a valuation that holds keeps that fear live.