The research looked at how introducing derivatives affected stock market volatility in India using the S&P CNX Nifty Index. They used a GARCH model to analyze the data and found that volatility patterns changed after derivatives were introduced. Before and after derivatives, there was clustering and persistence of volatility, but listing had no significant impact on market volatility. After derivatives, the relationship between index returns and market returns changed, and day-of-the-week effects disappeared.