Hong Kong stocks opened the session with a mixed tone, as the benchmark Hang Seng Index eased 64 points, or 0.25%, to settle at 25,453 points by the midday break. The Hang Seng Tech Index followed with a deeper decline of 0.75%. Total turnover for the morning session reached HK$126.8 billion, reflecting active trading despite the modest pullback in the broader market.

Mainland property developers emerged as the standout performers during the morning session, with a widespread rally across the sector. The positive sentiment was fueled by the successful launch of the "Shanghai Eight Measures" policy, which triggered a sell-out day for new housing projects over the weekend. Industry analysts suggest that housing prices in key cities are gradually approaching a bottom, providing support for the sector's rebound. Leading the charge, CH OVS G OCEANS (00081) surged 11%, while SUNAC (01918) advanced 7%, and COUNTRY GARDEN (02007) climbed 6%.

Contract research organization (CRO) stocks also delivered robust gains, ranking among the top performers in the morning trade. The rally was underpinned by better-than-expected earnings results from overseas CXO companies, which have reinforced expectations of a global demand recovery. ASYMCHEM (06821) led the pack with a 14% jump, while GENSCRIPT BIO (01548) added 7%, and TIGERMED (03347) rose 5%.

In the optical fiber segment, YOFC (06869) advanced 8.8% after reporting a stunning 889% year-on-year surge in first-half net profit. The exceptional performance was driven by simultaneous increases in both fiber prices and shipment volumes, which significantly boosted the company's top and bottom lines.

Meanwhile, KINGBOARD HLDG (00148) climbed over 8% after posting a 5% rise in interim net profit attributable to shareholders. The company's laminated paper segment saw a sharp increase in profitability, contributing to the overall earnings growth.

In the biotech space, JACOBIO-B (01167) soared more than 17% after swinging to a profit in the first half, with net earnings exceeding HK$600 million, a remarkable turnaround from the previous year's loss. EVEREST MED (01952) extended its gains with a further 10% advance, as its flagship drug Nefecon continues to gain market traction. The company's mRNA tumor vaccine pipeline is also entering a commercialization phase, adding to investor optimism.

CONANT OPTICAL (02276) rose more than 6% for a second consecutive session, as its extended reality (XR) business enters a volume shipment stage. The company's first-half revenue skyrocketed nearly 15-fold, underscoring the rapid scaling of its new product lines.

On the downside, gold-related stocks faced selling pressure after spot gold prices staged an intraday spike followed by a sharp pullback. LINGBAO GOLD (03330) dropped over 7%, while CHIFENG GOLD (06693) retreated 5.9%. In the aluminum sector, NANSHAN AL INTL (02610) fell more than 5% after reporting a 74.8% decline in first-half profit attributable to shareholders, weighed down by weaker alumina prices.

Casino operator NAGACORP (03918) also came under pressure, sliding over 5% after posting a 3.2% decline in interim net profit. The company's gross gaming revenue contracted by 8.6% during the period, reflecting softer demand in its key market.