KOSPI set to post worst session since March 2020
Circuit breakers activated for first time in four years
Authorities vow measures to calm extreme fear among investors

SEOUL, Aug 5 Reuters South Korean shares fell for a second straight session on Monday, with trading curbs activated for the first time in four years, as risk appetite dampened across global financial markets on U.S. recession fears.

The benchmark KOSPI fell as much as 8.1 in afternoon trade, after dropping 3.7 on Friday, and was set to post its worst session since March 2020.

The fall triggered trading curbs of sidecar and circuit breakers on the KOSPI for the first time since 2020. They were also activated on the junior KOSDAQ index.

A sidecar is activated when index futures fall or rise sharply and halts programme trading for five minutes to curb steep price movements. Circuit breakers, which halt all trading of stocks and derivatives for 20 minutes, are activated when indexes fall or rise more than 8.

In the broader Asian market, the MSCI Asia Pacific exJapan Index fell more than 2, while Japan39;s Nikkei dropped 10.

Chip heavyweights Samsung Electronics and SK Hynix lost more than 9, tracking steep declines in the Philadelphia Semiconductor Index, which had driven Wall Street39;s rally on optimism around artificial intelligence.

The KOSPI was down 14 from a sixmonth peak of 2,860.42 hit in July.

The market has entered territory of extreme fear amid a slump in U.S. big tech stocks, worries…