Investors have shown strong confidence in China's financial stocks, although foreign brokerage JPMorgan Chase & Co has advised reducing holdings in Chinese stocks and said China's bank stocks will fall.

Stocks soared in both Shanghai and Shenzhen markets on the Chinese mainland on Wednesday, led by securities companies and banks, sending the benchmark Shanghai Composite Index back to the 2,300 level. The index jumped 59.94 points, or 2.66 percent, to 2,317.37 points, the biggest gain since Jan 14. Trading volume was 10 percent higher than the 30-day average, while the 30-day volatility increased to its highest level since February 2012.

The Shenzhen Component Index closed at 9,317.97 points, up 3.14 percent, while the Hang Seng China Enterprises Index - mainland companies traded in Hong Kong - increased 2.22 percent.