# KOSPI trips circuit breaker after 8% fall, Nikkei down 4.8% as AI chip selloff hits Asia; KSE-100 flat

Source: Searchable (https://searchable.pk/news/markets/kospi-circuit-breaker-nikkei-falls-ai-chip-selloff-asia)
Type: News article
Author: Searchable Editorial
Published: 15 Oct 2026
Updated: 15 Oct 2026
Retrieved: 15 Oct 2026

> Samsung and SK Hynix lost about 10% each in Seoul as hot US inflation and AI debt worries spread from Wall Street. Pakistan's market barely moved.

**South Korea's KOSPI fell about 8% on Thursday, 15 October 2026, tripping a circuit breaker that halted trading, while Japan's Nikkei 225 dropped 4.8%** as a selloff in AI and chip stocks that began on Wall Street spread across Asia, [Business Recorder reported](https://www.brecorder.com/news/40444347/south-koreas-kospi-triggers-circuit-breaker-in-tech-led-selloff), carrying Reuters. Back home, the KSE-100 held steady near **166,455 points** at our 12:40pm PKT reading on our [KSE-100 data page](/data/kse-100).

## The numbers

- **KOSPI:** down 480.76 points to 5,528.05 by 03:38 GMT (8:38am PKT), its lowest since 29 July. It was the index's 10th circuit breaker this year and the 16th in its history, and a seventh straight losing session.
- **Samsung Electronics** fell 9.7% and **SK Hynix** 11.35%. Of 916 issues traded in Seoul, 855 fell.
- **Foreign selling:** foreigners sold a net 2.9 trillion won, about $2.15 billion (roughly Rs 595 billion at today's [dollar rate](/data/usd-pkr)).
- **Nikkei 225:** down 4.8% to 64,489.06 at the midday break; the broader **Topix** fell 2.5%, [Business Recorder reported](https://www.brecorder.com/news/40444359/japans-nikkei-plunges-as-tech-stocks-hammered-by-ai-rate-hike-worries). **Advantest** lost 13.9%, **SoftBank Group** 9.4% and **Tokyo Electron** 7.3%. Drug makers rose, with Sumitomo Pharma up 13%.

## Why markets fell

1. **Hot US inflation:** US consumer prices rose 3.7% in September, raising bets that the Federal Reserve will lift rates again and keep them high. Expensive, debt-funded tech stocks are hit hardest by that.
2. **AI debt worries:** reports of distressed debt at US cloud provider **CoreWeave** sent its shares down more than 15%, and Nomura's Wataru Akiyama said worries about AI companies' finances and spending had "risen quickly".
3. **Wall Street first:** the Nasdaq fell 1.9% on Wednesday and the Philadelphia Semiconductor Index 4.3%.

J.P. Morgan's Mixo Das said Seoul was "struggling to find a new buyer" now that share buybacks at Samsung and SK Hynix have ended, though he still expects AI stocks to be substantially higher in six to 12 months.

## What it means in Pakistan

- **PSX:** the KSE-100 has little exposure to global tech and was almost flat (166,455 against 166,333 at the previous reading). Its bigger risks are oil and the rupee.
- **Crypto:** bitcoin was near $81,200 and ether near $2,370 on our [bitcoin](/data/btc-usd) and [ether](/data/eth-usd) pages, after $483 million of bets were wiped out on Wednesday.
- **If you hold foreign shares** through an app or a Roshan Digital Account, gains and losses in rupees depend on the dollar too: run the figures through our [currency converter](/tools/finance/currency-converter).

Earlier today we reported that SK Hynix fell 10% and SoftBank 7.9% on the same inflation fears.

## Frequently asked questions

**Why did the KOSPI hit a circuit breaker on 15 October 2026?**

It fell about 8% as AI and chip stocks sold off after hotter US inflation raised bets on more Fed rate rises. Samsung fell 9.7% and SK Hynix 11.35%.

## Sources

- South Korea's KOSPI triggers circuit breaker in tech-led selloff (Business Recorder (Reuters)): https://www.brecorder.com/news/40444347/south-koreas-kospi-triggers-circuit-breaker-in-tech-led-selloff
- Japan's Nikkei plunges as tech stocks hammered by AI, rate hike worries (Business Recorder (Reuters)): https://www.brecorder.com/news/40444359/japans-nikkei-plunges-as-tech-stocks-hammered-by-ai-rate-hike-worries

How to cite: "KOSPI trips circuit breaker after 8% fall, Nikkei down 4.8% as AI chip selloff hits Asia; KSE-100 flat", Searchable, 15 Oct 2026, https://searchable.pk/news/markets/kospi-circuit-breaker-nikkei-falls-ai-chip-selloff-asia