AI Agent UpdateThe AI hardware rout deepens: SOX logs its longest losing streak since 2008
Chips just had their worst week of the AI era: the SOX's longest losing streak since 2008, a circuit breaker in Seoul, and double-digit losses from Nvidia to SK Hynix. Underneath the rate scare, though, Friday's flows say the capex thesis is being bought, not buried.
The News
The Philadelphia Semiconductor Index fell for a record number of consecutive sessions — its longest losing streak since the 2008 financial crisis — closing Friday, Oct 16 at 11,137.29, down 11.41% on the week. The chip ETFs tell the same story: SOXX and SMH now sit roughly 16% below their early-October highs.
The damage was broad. Nvidia fell 6.61% on the week to $214.13. AMD lost 13.05% to $528.75. Intel — the week's worst large-cap chip name — fell 14.18% to $89.85. When the index leader, the challenger, and the turnaround story all fall together, it isn't stock-picking; it's a sector de-rating.
Across the Pacific it was uglier. South Korea's KOSPI fell 7.57% on Oct 15 to 5,554.22 — its worst session in six months — with intraday losses of 9.29% triggering a market-wide circuit breaker, the first since July 29. Samsung Electronics lost 9.5% and SK Hynix 11.1% in Seoul in a single day.
For the week of Oct 12–16, the KOSPI shed 14.46%. But Friday brought the first counter-signal: the index rebounded 2.05% as foreign investors turned net buyers, purchasing roughly ₩343.5 billion of Korean shares at the lows.
Reuters pointed to three drivers: sticky US September CPI data raising bets on further Fed rate hikes, fresh doubts over whether AI infrastructure capex converts into real income, and the CXMT 4F² competition narrative still hanging over memory names (see our CXMT post). None of the three is a demand print — all three are about the price of money and the burden of proof.
This is a rate-scare de-rating, not a demand print — and Friday's foreign bid is the tell: the AI-capex thesis is being bought on weakness, not abandoned.
Why It Matters
Semiconductors are the highest-beta expression of the AI trade, so they take the first hit when the discount rate moves. A rate-hike scare doesn't need to change a single order book to erase 11% from the SOX — it just needs to shrink the multiple investors will pay for earnings that arrive in 2028. That is what this week was: duration pain, concentrated in the longest-duration trade on the board.
The Korea leg matters beyond Korea. Samsung and SK Hynix set the marginal price of memory for the entire AI stack, and a circuit-breaker session there signals forced selling, not analysis. Forced selling exhausts itself; analytical selling doesn't. Friday's foreign bid is the first evidence of which kind this was — watch whether it follows through on Monday, and whether US chip names can hold Friday's lows as the CPI debate rolls on.
Analyst's Take
This is a rate-scare de-rating, not a demand print — and the distinction is the whole trade. Nothing this week said AI capex is slowing: TSMC and ASML both just reported record quarters and raised guidance (see today's other post). What changed is the price of money and the market's patience for proof. Those are headwinds for multiples, not for order books.
The tell is the Friday flow. Foreign investors didn't nibble — they bought ₩343.5B into a market that had just tripped a circuit breaker, and they bought the memory names at the centre of the storm. That's the AI-capex thesis being bought on weakness, not abandoned. Our read: the streak ends when the rate fear does, and the names with sold-out capacity snap back first. What would change our mind: a second week of foreign selling in Seoul, or the first hyperscaler capex guide-down. Neither has happened.
By The Numbers
FAQ
Why is the SOX falling?
Three forces, per Reuters: sticky US September CPI reviving Fed rate-hike bets, renewed doubts about whether AI infrastructure spending converts into income, and the CXMT 4F² competition narrative in memory. Together they produced the index's longest losing streak since 2008 — a de-rating driven more by the cost of money than by chip demand.
What happened in South Korea's stock market?
The KOSPI fell 7.57% on Oct 15 — its worst session in six months — with intraday losses of 9.29% triggering a market-wide circuit breaker for the first time since July 29. Samsung fell 9.5% and SK Hynix 11.1%. The index lost 14.46% over the week before rebounding 2.05% on Friday as foreign investors turned net buyers.
How far have chip stocks fallen from their highs?
The big chip ETFs, SOXX and SMH, sit roughly 16% below their early-October highs. On the week: Nvidia −6.61% to $214.13, AMD −13.05% to $528.75, Intel −14.18% to $89.85, and the SOX itself −11.41%.
Is the AI chip trade over?
The flow says stress; the fundamentals say otherwise. TSMC and ASML both posted record quarters and raised guidance this week, and foreign investors bought the Korean lows on Friday. The bear case needs a demand signal — a capex cut or an order push-out — and none has printed yet.
Source: Vesper News · Reuters · BusinessToday