Korea's stock market fell 8 percent and stopped trading altogether for 20 minutes, a day after China's biggest memory chipmaker went public and quadrupled

South Korea's stock market stopped trading entirely for 20 minutes on Tuesday morning.

The Korea Exchange triggered a Level 1 circuit breaker at 10:13 a.m. in Seoul, with the KOSPI down 8.02 percent at 6,213.51. It was the eighth time the Korean market has hit a circuit breaker this year and the fourteenth time on record. The index was later quoted at 6,212.26, a fall of 543.49 points, taking it below 6,300 for the first time in more than three months.

The damage was concentrated in two companies. Samsung Electronics fell 9.45 percent to 230,000 won and SK Hynix fell 11.1 percent to 1,614,500 won, as the Korea JoongAng Daily's Jang Seo-Yun reported. Those two firms are the reason a chip story becomes a market story in Seoul: between them they account for roughly half the capitalisation of the index.

The selling was not confined to Korea. Japan's Nikkei 225 and Taiwan's Taiex each fell more than 4 percent on the same session.

The catalyst analysts pointed to happened the day before, in Shanghai. ChangXin Memory Technologies, the Hefei company that is China's largest producer of DRAM, listed on the STAR Market on Monday after raising 57.92 billion yuan, about $8.6 billion, at 8.66 yuan a share. That is the largest semiconductor offering ever done on the mainland and the largest initial public offering anywhere in Asia this year. The shares then rose 466 percent on their first day of trading, CNBC reported, which made ChangXin the most valuable company listed on China's mainland exchanges.

Analysts quoted by the Korea JoongAng Daily tied Tuesday's fall to that listing, on the reasoning that the proceeds fund a competitor to Samsung and SK Hynix, and to broader concern about competition and oversupply in global memory. Separate reports that Chinese firms have begun developing domestic deep ultraviolet lithography equipment, the machinery used to pattern advanced chips, also weighed on sentiment. Those same reports helped push American chip stocks lower on Monday.

The New York session that preceded all this was mixed rather than bad. The Dow Jones Industrial Average closed up 262.83 points, or 0.51 percent, at 52,210.08. The S&P 500 added 0.02 percent to finish at 7,413.18. The Nasdaq Composite fell 0.18 percent to 24,932.08. Underneath those numbers the chip complex was clearly under pressure: Advanced Micro Devices fell about 5 percent and Teradyne about 4 percent, the VanEck Semiconductor ETF lost more than 2 percent, and Micron Technology shed about 2 percent.

American futures moved only modestly overnight. S&P 500 futures were down 0.3 percent and Nasdaq 100 futures down 0.2 percent, while Dow futures were higher by 24 points, or 0.05 percent.

The Federal Open Market Committee convenes on Tuesday for a two-day meeting, with a decision due Wednesday.

A note on sourcing. The Korea Exchange records its circuit breakers through a market data portal that serves pages from a session rather than from a fixed public address, so there is no primary document linked here. No public filing has been released. The index levels, the trigger time and the two Korean share prices in this item come from the Korea JoongAng Daily's report, credited above; the New York closing figures and the overnight futures come from the market close and from CNBC's markets coverage. Asian markets were still trading as this was written, so the Korean and Japanese numbers are intraday and will move.