Live markets-Yen sinks as BOJ holds - and it's the KOSPI's best day

Currency markets, meanwhile, were processing the implications of unprecedented coordinated intervention by Japanese and Korean foreign exchange authorities on Thursday to strengthen their respective currencies against the U.S. dollar. For Tokyo, it was the latest in a string of market forays by authorities this year to halt the yen's decline, but it was a rare move by Seoul.

The intervention boost didn't last long for the yen JPY=, which fell on Friday to 160.69 after the Bank of Japan's rate-setting committee kept rates on hold, in line with market expectations. The won also reversed some gains after reaching its strongest level in nine months overnight.

What a wild ride. Markets in Asia staged a blistering rally on Friday after the scorching selloff in tech stocks earlier this week, while the yen resumed its descent as the Bank of Japan left interest rates on hold.

South Korea's KOSPI .KS11 blasted as much as 17% higher, alongside gains of more than 7% in Taiwan .TWII and a jump of more than 5% in Japan's Nikkei 225 .N225 as traders pounced on battered chipmaker shares. MSCI's broadest index of Asia-Pacific shares outside Japan .MISX00000PUS was up 4.7%.