The single-stock circuit breakers introduced after the May 6, 2010 “flash crash” were not as disruptive as many people feared they would be, according to a report released by Credit Suisse. Titled “Pardon the Interruption -- The Impact of Trading Halts,” the report found that 51% of trading halts from June 2010 to September 2011 came after fundamental news emerged about a stock. In these cases, the appropriate price adjustment still occurred, but was postponed, the report found. The circuit breakers are potentially undesirable to some market participants who are looking to profit from a first-mover advantage. Still, exchanges already halt stocks when certain news is pending to allow investors time to digest all the relevant information. When important news is released during trading hours without advance warning, circuit breakers can allow an orderly adjustment process in which market participants have time to correct for imbalances before submitting their orders, the report found. About 11% of circuit breakers were triggered by a “fat finger” trade that temporarily throws a stock’s price out of line before the price reverts to its previous level. In these cases, circuit breakers are definitely helpful, as they prevent prices from being pushed way beyond fair value as other traders react to one outlying price. Bad prints caused about 6% of trading halts, the report found. For this small number there is a definite disadvantage, as the market can easily identify a mistaken print and move on, but the circuit breaker delays that process. Overall, however, there were only a few occurrences where circuit breakers could be considered truly disruptive, the report found. Others were considered beneficial, or at worst, a nuisance. The report pointed out that even with the halts, U.S. stocks still trade more consistently than stocks in many other developed countries where trading can be stopped for hours or days around important news events. Currently, the Securities and Exchange Commission plans to replace the single-stock circuit breakers with a proposed limit up/limit down rule, which would introduce a pause for 15 seconds before enacting a full trading halt. [Trader's, 10/25/11