During the Global Financial Crisis, regulators imposed short-selling bans to protect financial institutions. The rationale behind the bans was that "bear raids", driven by short-sellers, would increase the individual and systemic risk of financial institutions, especially for institutions with...

Did the August 2011 European short sale bans on financial stocks accomplish their goals? In order to answer this question, we use stock options' implied volatility skews to proxy for investors' risk aversion. We find that on ban announcement day, risk aversion levels rose for all stocks but more...

This paper investigates whether the overpricing of out-of-the money single stock calls can be explained by Tversky and Kahneman's (1992) cumulative prospect theory (CPT). We argue that these options are overpriced because investors' overweight small probability events and overpay for such...