This dissertation investigates the information considerations of volatility, pricediscovery and the relationship change in volume and volatility resulting from index derivatives transactions on financial markets in Australia. The impact of information on volatility was investigated in the essay one, as volatility is a key factor for accurately pricing derivative securities. I assessed the forecast accuracy, unbiasedness and information content of volatility forecasts, based on implied volatility and conditional volatility models for the S&P/ASX 200 Index Options market in Australia. The conditional volatility models produce the most accurate forecasts and are robust when forecasting into short time horizons. Essay two, investigates the information content of the index and option markets in the price-discovery process. Based on the above volatility results, the long-run equilibrium relationship between the share price index and the implied price of the share-price-index option was investigated. Causality was determined to show which market leads the other. Information share measures were used to gauge the contribution of the share price index and index option markets to the price-discovery process. Unambiguous evidence shows the index market leads the options market and the former contributes more to price-discovery than the latter. In essay three, I investigate the dynamic relationship between the future price volatility of the S&P/ASX 200 Index and the trading volume of the S&P/ASX 200 Index Options to explore the informational role of option volume in predicting price volatility. I found the contemporaneous call options volume have a significant strong positive feedback effect on the implied volatility, but the contemporaneous feedback effect of volume on the TARCH volatility is insignificant. The contemporaneous feedback effects from the implied volatility and the TARCH volatility to the call options volume are positive, significant and strong.