06:46 AM EDT, 06/23/2026 (MT Newswires) -- Asian stock markets retreated Tuesday, following overnight signals on Wall Street that the tech- and AI-sectors may have become over-extended after recent rallies.

Hong Kong, Shanghai and Tokyo finished in the red, while Seoul's KOSPI index tumbled 10%, as heavyweight semiconductor issues such as Samsung Electronics and SK Hynix both declined more than 12%.

Brent crude oil futures edged lower during Asian market hours, off 0.2% to $77.71.

In Japan, the Nikkei 225 opened evenly but declined throughout the day, finishing off 3.6% as traders booked profits in a market that on Monday struck an all-time zenith, and which then was up more than 80% on year.

Investors also mulled possible tightening by the Bank of Japan and other monetary authorities, as the Japanese yen traded to more than 161 to the US dollar, the lowest exchange rate in 40 years.

The benchmark Nikkei 225 fell 2,565.58 to 69,788.38, as losing issues outnumbered gainers 183 to 41.

Leading the upside was electronic-components maker Fujikura, up 5.3%, while Furukawa Electric declined 15.5%.

In economic news, Japan's flash composite purchasing managers index (PMI), a combination of the nation's manufacturing and services sectors, rose to 52.5 in June from 51.1 in May, marking the 15th straight month of expansion in private-sector activity, reported S&P Global.

In Hong Kong, the Hang Seng Index opened evenly but sagged in the afternoon, closing down 1.8% as traders again backed away from tech and property shares.

The broad gauge Hang Seng fell 432.24 to 23,336.28, as losing issues outnumbered gainers 73 to 19. The Hang Seng TECH Index lost 3.3% on the day, while the Mainland Properties Index fell 1.8%.

Leading the upside was Geely Automobile, gaining 2.1%, while metals-house CMOC declined 10.9%.

On the mainland, the Shanghai Composite fell 1.4% to 4,106.25.

On the other regional exchanges, the Taiwan TWSE declined 1.3%; the Australian ASX 200 declined 0.3%; the Singapore Straits Times Index was steady, and the Thai Set declined 2.1%. In late trading in Mumbai, the Sensex was down 1.3%.

The MSCI All Country Asia Pacific Index fell 3.5% on the day.