BEIJING/SHANGHAI - ‍China's securities regulator ‍vowed to step up market monitoring ​and crack down on excessive speculation, as the country's ⁠benchmark stock index hovered near a decade high with ⁠record turnover this ‌week.

The statement came after Chinese bourses said on Wednesday that they would raise ⁠the minimum margin requirement for new borrowings to 100% from 80%, effective January 19, a move approved by the regulator and aimed at ⁠cooling the red-hot market.

The ​Shanghai Composite Index has gained 6% over the past month.

The China ‍Securities Regulatory Commission said in a statement it would carry ​out timely counter-cyclical adjustments and strengthen supervision over trading activities and information disclosure.

The regulator also said it will crack down on illegal activities such as excessive speculation and market manipulation, aiming to sustain the market's positive momentum.

Recent weeks have seen hectic trading in sectors such as artificial intelligence, aerospace and robotics, ⁠prompting risk warnings from listed firms.

Onshore ‌share turnover hit nearly 4 trillion yuan on Wednesday, the highest on record.

(Reporting by Yukun ‌Zhang and ⁠Ryan Woo in Beijing, and Li Gu in Shanghai; ⁠Editing by Jacqueline Wong, Elaine Hardcastle)