Mainland stocks edged down on Friday, ending the week lower after a four-week winning streak, as regulators tightened margin financing rules and vowed to crack down on excessive speculation to cool down sentiment.

In Hong Kong, the benchmark Hang Seng Index ended down 78 points, or 0.29 percent, at 26,844.

The tech index was six points, or 0.11 percent, down at 5,822 while the China enterprises index was down 46 points, or 0.5 percent, at 9,220.

On the mainland, the benchmark Shanghai Composite Index was down just over 10 points, or 0.26 percent, at 4,101 while the Shenzhen Component Index was 25 points, or 0.18 percent, lower at 14,281.

The ChiNext Index, tracking China's Nasdaq-style board of growth enterprises, lost close to seven points, or 0.2 percent, to end at 3,361.

For the week, the Shanghai Composite Index was down 0.5 percent, ending ⁠a run of gains since mid-December, while the Hang Seng Index rose 2.3 percent.

China's securities regulator pledged to "comprehensively" step up market monitoring and "resolutely" prevent sharp fluctuations, according to a statement released on Friday.

The People's Bank of China announced cuts to sector-specific interest rates on Thursday to provide an early boost to the economy, signalling room for further reductions in banks' cash reserve requirements and for broader rate cuts this year.

"The moves were a positive surprise as they gave a clear signal on monetary policy stance," said UBS economists in a note.

"It is difficult to reflate the economy without further policy loosening."

The market's mood ⁠was dampened this week after the Shanghai, Shenzhen and Beijing bourses said they would raise the minimum margin requirement for new borrowings to 100 percent from 80 percent, effective January 19.

Onshore semiconductor shares rose 3.4 percent, as TSMC, the world's main producer of advanced artificial intelligence chips, on Thursday posted a forecast-smashing 35 percent jump in fourth-quarter profit to a record high, predicted robust annual growth and flagged that more US manufacturing capacity was in the works.

Non-ferrous metal shares were down 0.9 percent.

They were up nearly five percent this week. (Reuters/Xinhua)