1. The decrease came as at least one type of trading collar that restricts program trading was triggered each day. 2. The New York Stock Exchange imposed its trading collars a record four times today, as investors weathered the most volatile month for stocks in at least a year. 3. The NYSE also imposes trading collars, which restrict some computer-driven trading. 4. The trading collar was still in place at the close. 5. These trading collars restrict index-arbitrage trading. |