NEW YORK (MarketWatch) -- Trading curbs have been put in place Thursday at the New York Stock Exchange, the NYSE said. The curbs, or "collars", are meant to slow trading transactions to reduce market volatility. The curbs are triggered when the NYSE Composite Index drops or rises 190 points and are removed when the index returns to within 90 points of the previous day's close. The NYSE Composite was recently down 178 points at 10,132.