41.   Some analysts say one reason is that those indexes are often used in sophisticated trading strategies known as arbitrage.

42.   Some traders use technical analysis, or the study of historical price patterns, to determine trading strategies.

43.   Still, short interest can also increase as a result of complex trading strategies involving options, futures and other stock-related derivatives.

44.   Still, short interest can increase as a result of complex trading strategies involving options, futures and other stock-related derivatives.

45.   Studying the past is part of his trading strategy.

46.   Still, short interest can also rise as a result of complex trading strategies involving options, futures and other stock-related derivatives.

47.   Still, short interest can rise as a result of complex trading strategies involving options, futures and other stock-related derivatives.

48.   Stock swung wildly throughout the day, roiled by short-term trading strategies, traders said.

49.   Sumitomo said that an internal investigation was continuing, and that it had shed little light on the trading strategies involved.

50.   The agency served notice Tuesday that it will request data related to energy trading strategies from all wholesale suppliers in California.