Hong Kong stocks fell on Monday following a holiday as investor sentiment waned after China's finance ministry failed to specify further stimulus measures for the economy.

The Hang Seng Index fell 0.75%, or 159.11 points, at 21,092.87. The Hang Seng China Enterprises index lost 0.54%, or 40.80 points, at 7,579.94.

Finance minister Lan Foan hinted at significantly increasing debt at a press conference held over the weekend but failed to provide any details on the size of the stimulus, leaving investors speculating.

Investor sentiment also took a hit as data from the statistics bureau on Sunday showed consumer inflation decelerating to 0.4% in September from 0.6% in August and producer prices plunging 2.8% for the 24th straight month, according to an SCMP report.

Pharma companies BeiGene (HKG:6160, SHA:688235), Innovent Biologics (HKG:1801), and CSPC Pharmaceutical (HKG:1093) led the decline with each of the companies' shares falling 5% at the close.

Sporting goods manufacturer Anta Sports Products (HKG:2020) also plunged 9%, with EV maker BYD (HKG:1211, SHE:002594) dropping 4% at Monday's close.