The Hang Seng Index fell 126.48 points, or 0.7 percent, to open at 17,862.59 points on Monday.

This comes as investors in the US have reportedly been switching from tech stocks, following results from tech giant Nvidia, into shares more likely to benefit from this month's expected interest rate cut.

The US central bank, the Federal Reserve, is expected to kick off a rate-cutting cycle at its monetary policy meeting on September 17-18.

With the Hong Kong dollar pegged to the US dollar, any interest cut in the US should also lead to cuts in the SAR. (with additional reporting from Xinhua and Reuters)