Hong Kong's Hang Seng falls 6% in mixed Asia trade; Japan's currency declines despite intervention reports.

On Monday, major markets across Asia and the Pacific climbed, but Hong Kong and mainland China markets sank dramatically.

The Hang Seng index in Hong Kong plunged 6.36 per cent to 15,180.69, its lowest level since April 2009. The Hang Seng Tech index fell more than 9 per cent.

According to Tai Hui, APAC senior market strategist for JPMorgan Asset Management, the Hong Kong market has been driven by several factors, including rising yields on U.S. Treasuries.

Xi Jinping's allies were selected to form a core leadership group at the CPC's 20th National Congress over the weekend. Investors may have expected policy measures to be unveiled at this time.

In an email to CNBC, Tai said, "Since the conference is mainly about personnel changes, the economic rebound might not happen as soon as we have hoped."

Mainland As better-than-anticipated economic data boosted Chinese stock markets, those gains were quickly erased, and the country's markets began their downward spiral again. The Shanghai Composite Index on the mainland went down 2.02% to 2,977.56, and the Shenzhen Component Index went down 2.05% to 10,694.61.

The S&P/ASX 200 index in Australia rose 1.54 per cent to 6,779.40. In South Korea, the Kospi rose 1.04 per cent to 2,236.16, and the Kosdaq rose 2.08 per cent to 688.50.

The Nikkei 225 in Japan increased by 0.31 per cent to 26,974.90 points, and the Topix gained 0.28 per cent, closing at 1,887.19. The MSCI Asia ex-Japan broad share index fell by 1.94%.

On Friday, the Japanese government reportedly intervened in the foreign exchange market, which led to a significant appreciation of the yen. However, the fluctuation of the currency persisted. Monday morning in Asia saw a brief strengthening to the 145 level before settling back down to the 149.25 level against the dollar.

U.S. stocks soared Friday as the Wall Street Journal reported some Fed officials are anxious about tightening too aggressively. The Dow increased 748.97 points (2.47%) to 31,082.56 on Friday. S&P 500 up 2.37 percent to 3,752.75 Nasdaq Composite rose 2.3% to 10,859.72.

The stock exchanges in Singapore, Malaysia, and India will be closed on Monday due to holidays. Singapore and Australia are anticipated to announce inflation statistics later this week, while the Bank of Japan will have a meeting later.