HONG KONG - Hong Kong shares were flat at midday on Thursday to stand on the brink of snapping a nine-day winning streak that has taken the Hang Seng Index to highs for 2012, as investors took profits and third-quarter corporate earnings drove bigger price movements.The Hang Seng Index was almost unchanged at the midday trading break, hovering at a 2012 closing high recorded on Wednesday. The benchmark is now up almost 14 percent from a Sept. 5 low and 18 percent since the beginning of the year.Its 14-day relative strength index (RSI) hovered at two-year highs on Friday after hitting 78.1 on Thursday, its highest since Oct 15, 2010. A reading above 70 could suggest the benchmark is overbought, while a reading below 30 could indicate the market is oversold.In the mainland, the Shanghai Composite Index and the CSI300 Index of the top Shanghai and Shenzhen listings each slipped 0.2 percent. The China Enterprises Index of the top Chinese listings in Hong Kong lost 0.4 percent."You have to realize we are now in the fourth quarter, so hedge fund managers will now be looking to lock in some profits after the rally from early September," Hong Hao, chief equity strategist at Bank of Communication (BoCom) International Securities, told Reuters.