AI Chip Plunge: From Bubble Warnings to Korea's Circuit Breakers

Episode 1 · Gary Marcus Warns of AI Stock Bubble as CoreWeave and Oracle Plunge (2026-07-24, 3 posts)

Gary Marcus warns that volatile AI tech stocks are increasingly resembling cryptocurrencies. He highlights a significant market cooldown, noting that CoreWeave and Oracle have both plunged by about a third from their peaks.

• Gary Marcus says AI-heavy tech stocks now trade like crypto — GaryMarcus · 2026-07-24
• CoreWeave and Oracle have both lost more than a third as AI trade unwinds — GaryMarcus · 2026-07-25
• Marcus says the AI trade is under stress as CRWV and ORCL slide sharply — GaryMarcus · 2026-07-25

Episode 2 · South Korea AI Chip Stocks Plunge 10.84%, Global Compute Narrative Repriced (2026-07-28, 8 posts)

Global chip and AI stocks have experienced a sharp selloff, with South Korea's market becoming the center of a 'stress test' for the AI compute boom. Concerns over the sustainability of AI infrastructure spending and return on investment drove the KOSPI index down 10.84% in a single day, triggering circuit breakers. Samsung Electronics fell 9.15% and SK Hynix dropped 10%. Market views generally hold that this is not a single fundamental deterioration but a repricing of the AI compute narrative by capital.

Confirmed

• South Korea's KOSPI plunged 10.84% to a multi-month low, with Samsung Electronics down 9.15% and SK Hynix down 10%.
• SK Hynix reported 257% revenue growth in its latest earnings, yet its stock fell about 20% post-earnings.
• South Korea's compute supply chain is extremely concentrated: Samsung and SK Hynix account for nearly half of KOSPI's weight, and retail investors hold about $23 billion in margin loans.
• CDS spreads for hyperscale data centers have widened, raising debt concerns, but GPU spot premiums of 2x and profits from agentic inference may offset some risks.

Unconfirmed

• The extent to which substantive breakthroughs in Chinese memory chips and DUV technology (some views compare progress to ASML in 2008) will disrupt existing closed AI alliances and market pricing remains uncertain.

Why it matters

• This selloff marks a turning point in market sentiment, as investors begin to scrutinize the actual returns on massive AI capital expenditures, shifting the trading logic for compute infrastructure.
• The extremely concentrated supply chain and high leverage (e.g., leveraged ETFs and fund profit-taking) amplify downside risks, exposing the vulnerability of AI compute alliances to cheaper competitors.

• AI spending worries push Samsung and SK Hynix down more than 10% — nordicinst · 2026-07-28
• FT screenshots show AI chip optimism and a sharp sell-off in the same day — nathanbenaich · 2026-07-28
• BofA-linked take says the semis/AI selloff may be narrative-driven, not one clear break — toptickcrypto · 2026-07-29
• Chip selloff sparks a warning that AI cartels are unstable when cheaper rivals emerge — beffjezos · 2026-07-29
• South Korea’s AI-linked stocks sink 10.84% as Samsung and SK Hynix plunge — emmanuelvivier · 2026-07-29
• South Korean Stock Market Plunges 10.84% Amid AI Boom Doubts, SK Hynix and Samsung Fall — emmanuelvivier · 2026-07-29
• Three Stories Behind the Semi Selloff: Hyperscaler CDS, SK Hynix Earnings, China's DUV — bookwormengr · 2026-07-30
• Korean AI Chip Stock Plunge Highlights Global Compute Supply Chain Concentration — srimisra · 2026-07-30

Episode 3 · Korean Authorities Intervene as AI Chip Stock Selloff Triggers Market Crash (2026-07-29, 4 posts)

South Korean financial regulators have implemented emergency market-saving measures after AI stock fears and disappointing SK Hynix earnings triggered a historic crash. The KOSPI index plummeted, triggering circuit breakers and falling 41% from its peak.

• South Korea’s AI-chip rally unwinds as KOSPI drops 41% from its peak — SumitGup · 2026-07-29
• SK Hynix miss sends AI chip stocks tumbling and drags Korea’s Kospi lower — nordicinst · 2026-07-29
• AI stock sell-off sends South Korea’s Kospi into a historic two-day plunge — eyishazyer · 2026-07-29
• South Korean Authorities Scramble to Save Stock Market From AI Bubble — return2ozma · 2026-07-30

Episode 4 · Gary Marcus Warns of AI Stock Decline and Bubble Risks (2026-07-30, 2 posts)

Gary Marcus highlights a significant downturn in AI-related stocks, fueling bubble concerns. CoreWeave hit a 52-week low, Oracle neared its lows, and Nvidia dropped nearly 9% over the past three months.

• Gary Marcus flags fading AI-stock momentum as bubble worries grow — GaryMarcus · 2026-07-30
• AI Infrastructure Stocks Cool Down: CRWV at 52-Week Low, NVDA Down 8.69% — GaryMarcus · 2026-07-30