Hong Kong brokers believe United States financier George Soros was again behind the heavy trading in Taiwanese technology stocks this week. The stocks spearheaded Wednesday's rally, which saw the Taiwan benchmark index jump to a four-month high. Taiwan Semiconductor Manufacturing and other computer-related issues were among the top gainers. Brokers were confident computer-related companies would continue to post good profits growth this year. Companies that make computers and components had sales increases of more than 30 per cent last month. Among the most active stocks was Taiwan Semiconductor, the world's biggest producer of computer chips to clients' designs, and United Microelectronics and Advanced Semiconductor Engineering. Shares of Yageo, an electronics company, soared as investors speculated that Mr Soros might have bought the stock. The company's chief financial officer, Jerry Leen, said a Soros representative was planning to visit the company in the next few days. Mr Soros' Quantum Fund, the flagship of a group of seven hedge funds, is believed to be active in the market. The Quantum Group of Funds, which has almost US$19 billion in assets under management, are high-risk hedge funds.