LAST week's Hang Seng Index drama was evidence of a word often used recently to describe the stock market - volatile. It plunged early in the week, before doing an about-turn to hit records for two successive days. The dive started on Tuesday, when the Commercial Crime Bureau raided seven listed companies. But many brokers put the fall down to a technical consolidation, with the raids simply serving as an excuse. Then on Thursday the index started its climb, spurred by the high price fetched for a Kowloon site in Wednesday's land auction. But with the index at the present dizzying level of 10,568.86, more cautious investors may wonder if it will now jump at any excuse to consolidate again. A few brokers warn that the market is looking risky, considering its high volatility, although most remain bullish enough to tip 11,000 or even 12,000 as an attainable level by the year-end. ''We could see some consolidation [this week],'' said SBCI Finance Asia associate research head Philip Pritchard, adding that some institutions would be packing up for the Christmas holidays. ''The market will be moving up and down. It may break another record and test the 11,000 level,'' said GK Goh Securities dealing manager Bobby Ho. Grounds for the optimism include overseas money continuing to flow in during the past few weeks, even in the face of political uncertainties and in the absence of positive developments on either the political or economic front. For overseas institutions, the only buzzword seems to be bullishness - of which brokers can so far see no end. The big surges on Thursday and Friday were made on the back of bumper turnovers around $10 billion. December futures were also trading at a widening premium. And trading of Hong Kong stocks in London on Friday night showed no major selling pressure either. Flat trading in London left the market only about eight points weaker than Friday's local close, according to an index estimate calculated by Robert Fleming in London. The record close of 10,568.86 set on Friday compares with the 12-month low of 5,242.48 hit on December 21 last year. At Friday's local close, the index had gained 320.3 points, 3.13 per cent, over the previous five days, 1,304.95 points or 14.09 per cent from one month ago, 3,178.29 points or 43 per cent from three months ago, and 5,376.23 points or 103.54 per cent from a year ago. Of the index constituent stocks, the finance sector fared best last week, gaining 7.39 per cent. Properties came off second best, rising 5.19 per cent. Utilities was the only sector to lose ground, dropping by 1.35 per cent. In the futures market, roll-over activity is expected to gain momentum in the run-up to the end of the month. Investors last week were already switching their interest from December to January contracts. On Friday, January contracts accounted for 18.5 per cent of total activity, compared with 3.9 per cent on Monday. Among individual stocks, Hang Seng Bank was last week's best performing index constituent, gaining 13.18 per cent to $73.