Hong Kong stocks posted their biggest gain of the month so far yesterday as the banks' mortgage war continued and oil and commodity prices rebounded. However, traders were still cautious on the outlook for the rest of the week because of the results season and Financial Secretary Henry Tang Ying-yen's budget speech tomorrow. The Hang Seng Index rose 122.98 points or 0.79 per cent to finish at 15,598.67, continuing its five-day winning streak while the H-share index jumped 146.39 points or 2.29 per cent to settle at 6,526.34. Shares worth $27.36 billion changed hands compared with $25.4 billion recorded on Friday. Property stocks shone as investors expect the lower mortgage rates offered by banks to send property prices up. The increase in sales of new flats was also read as a good indication of a bullish property market. Macquarie Research analyst Eva Lee said in its daily market preview: 'The widening of the mortgage discount to prime will immediately strengthen buyer sentiment and alleviate the interest burden of end-users. 'This also raises market expectations that we are approaching the end of interest rate rises. 'Property buying interest will continue to return to the market and thereby boost volumes and prices.' But Prudential Brokerages associate director Kingston Lin was sceptical. 'The extent to which the banks' decision to cut mortgage rates helps boost the property prices remains to be seen,' he said. He reminded investors that developers would be announcing their results over the next few weeks and this could cause some volatility in the market. However, the property sub-index outperformed the benchmark, rising 1.3 per cent to 19,091.81 points. Cheung Kong surged 2.15 per cent to $80.60 and Henderson Land rose 1.92 per cent to $39.70. New World Development, which is included in the commercial sub-index, jumped 2.59 per cent to $11.85, being the second-best index gainer and leading all blue-chip developers. HSBC has lifted the mortgage discount to 2.75 percentage points below prime from 2.5 points. The bank's prime rate is 7.75 per cent. Oil, gold and metal plays were also in demand yesterday. CNOOC, China's top offshore oil producer, climbed 3.96 per cent to $6.55 while the third-most active stock, PetroChina, jumped 3.4 per cent to $7.60. That was in line with advancing oil prices which leapt more than US$1 after Nigerian militants crippled production and threatened more violence in the world's eighth-largest exporter of crude oil. Aluminum Corp of China surged on expectations that alumina prices would climb further after their rise during the Lunar New Year holiday. The mainland company, which makes 90 per cent of China's alumina, jumped 6.29 per cent to $7.60, leading all the players on the H-share index. China financials, meanwhile, started another rally after last week's consolidation with China Construction Bank jumping 4.19 per cent to $3.725, Bank of Communications adding 4.27 per cent to $4.875 and China Life Insurance surging 4.14 per cent to $8.80.