Japan's Nikkei logs worst day since 1987 Black Monday crash

Japan stocks confirmed a bear market on Monday as Asia-Pacific markets continued the sell-off from last week, with the Nikkei 225 and Topix dropping over 12%.

The benchmark indexes have fallen more than 20% from their all-time highs on July 11.

The 12.4% loss on the Nikkei — which saw it close at 31,458.42 — was the worst day for the index since the "Black Monday" of 1987. The loss of 4,451.28 points on the index was also the largest in terms of points in its entire history.

The Nikkei erased all its gains so far this year, moving into a loss position.

The broad-based Topix also saw a rout as it tumbled 12.23% and closed at 2,227.15.

Heavyweight trading houses such as Mitsubishi, Mitsui and Co, Sumitomo and Marubeni all plunged over 14%, with Mitsui losing almost 20% of its market cap.

Monday's decline follows Friday's rout when Japan's Nikkei 225 and Topix fell more than 5% and 6%, respectively.

In Monday trading, the yen also strengthened to its strongest level against the dollar since January, and was last trading at 142.09.

South Korea's Kospi fell 8.77%, closing at 2,441.55, and the small-cap Kodaq tumbled 11.3%, ending at 691.28.

Due to the magnitude of the sell-off, the exchanges hit circuit breakers, halting trade for the Kospi index at 2.14 p.m. Seoul time and at 1.56 p.m. for the Kosdaq. The halt was for 20 minutes. Circuit breakers are activated if stocks rise or fall 8%.

Investors, meanwhile, awaited key trade data from China and Taiwan this week, a well as central bank decisions from Australia and India.

China's service sector expanded at a faster pace in July, with the country's purchasing managers' index climbing to 52.1 in July, up from 51.2 in June.

The Caixin survey said the acceleration of growth was due to