The informative role of trading volume in an expanding spot and futures market

• In all three periods the impact of trading volume on volatility is negative.
• The impact of volume on volatility has weakened after the introduction of options.
• The introduction of futures trading leads to a decrease in spot volatility.
• Spot trading volume decreases after the introduction of option contracts.
• Significant expiration day effects on the value of shares traded and volatility.

This paper investigates the information content of trading volume and its relationship with range-based volatility in the Indian stock market for the period 1995–2007. We examine the dynamics of the two variables and their respective uncertainties using a bivariate dual long-memory model. We distinguish between volume traded before and after the introduction of futures and options trading. We find that in all three periods the impact of both the number of trades and the value of shares traded on volatility is negative. This result is consistent with the argument that the activity of informed traders is inversely related to volatility when the marketplace has increased liquidity, an increasing number of active investors and high consensus among investors when new information is released. We also find that (i) the introduction of futures trading leads to a decrease in spot volatility, (ii) volume decreases after the introduction of option contracts and (iii) there are significant expiration day effects on both the value of shares traded and volatility series.