These two essays demonstrate the important role that derivative markets play in assimilating information into financial markets. In the first essay I use the 2008 short-selling ban to examine the impact of single-stock futures (SSFs) trading on options market quality. I show that there is a substitution effect between options trading and SSFs trading during the ban period. In addition, my results show that SSFs trading had a significant effect in narrowing the bid-ask spreads of options contracts. Moreover, compared to stocks without SSFs, stocks with SSFs were less likely to violate put-call parity during the ban period. My results suggest that SSFs trading helps mitigate the negative effect of the short-selling ban on options market quality documented in the literature.In the second essay I look at information flows through large option trades. The motivation comes from CNBC's "Halftime Report" which regularly covers unusual option activity, i.e., those abnormally large trades, and recommend investors to follow the "smart money". I investigate the impact of the CNBC coverage on underlying stock prices and whether investors can indeed profit by following the "smart money". I document an immediate spike in trading volume and abnormal returns at the time of the CNBC coverage, and evidence that the unusual option trades are informative of stock prices around the coverage. However, I also document a significant reversal in underlying stock prices following the CNBC coverage. Using the same criteria advocated by the CNBC commentators, I identify unusual option activities for a large sample of stocks without CNBC coverage. I confirm that the unusual option trades significantly predict underlying stock returns, but find no evidence of reversal in underlying stock prices. My findings suggest that the CNBC coverage of unusual option activity has a destabilizing effect on underlying stock prices and investors cannot profit by simply following the CNBC reporting on the "smart money".

This dissertation consists of two essays on crude oil futures and options markets. The first essay investigates whether aggregate risk aversion and risk premiums in the crude oil market co-vary with the level of speculation. Using crude oil futures and option data, I estimate aggregate risk aversion in the crude oil market and find that it is signi ficantly lower after 2002, when speculative activity started to increase. Using speculation index as a state variable, risk premiums implied by the state-dependent risk aversion estimates confi rm the negative correlation between speculative activity and risk premiums, and indicate that risk premiums in the crude oil market are on average lower and more volatile after 2002. These findings suggest that index-fund investors who demand commodity futures for the purpose of portfolio diversi fication are willing to accept lower compensation for their positions. Estimated state-dependent risk premiums have substantial predictive power for subsequent futures returns and outperform commonly used predictors. The second essay exams the economic importance of jumps, jump risk premiums, and dynamic jump intensities in crude oil futures and options markets. Existing pricing models for crude oil options are computationally intensive due to the presence of latent state variables. Using a panel data of crude oil futures and options, I implement a class of computationally e fficient discrete-time jump models. I find that jumps account for about half of the total variance in crude oil futures and options prices, and a substantial part of the risk premiums is due to jumps. Jumps are large and rare events in crude oil futures and options markets. The main role of jumps and jump risk premiums in crude oil futures and options markets is to capture excess kurtosis in the data. These findings suggest that it is critical to include jumps in pricing models for crude oil futures and options, and there is strong evidence in favor of time-varying jump intensities.