At the end of January 2021, a group of stocks listed on US stock exchanges experienced sudden surges in their stock prices, which - coupled with high short interest – led to brief short squeeze episodes. We argue that these short squeezes were the result of coordinated trading by retail...

On October 26, 2008, Porsche announced a largely unexpected domination plan for Volkswagen. The resulting short squeeze in Volkswagen's stock briefly made it the most valuable listed company in the world. We argue that this was a manipulation designed to save Porsche from insolvency and the...

We contrast two different asset pricing models, where the pricing kernel either (i) increases in the volatility dimension, reflecting investors' aversion to volatility, or (ii) could be non-monotonic in volatility, reflecting heterogeneity in investors' beliefs. The two models yield opposite...

This paper studies the predictability of S&P500 returns using short term risk premia as a conditioning variable. We construct dividend prices using futures data and identify short term risk premia by projecting excess returns of dividend claims on their lagged prices. Regression results for...

We model the S&P500 index options dynamics using the CGMY distribution, with independent "up" and "down" return jumps, and diffusive jump intensities. Allowing the up and down parts to be separately parameterised accounts for the dynamic smirk effect, without correlation between returns and...

This paper exploits a natural experiment from the late 1800s in which many U.S. firms had inadvertently issued both taxable and tax-exempt bonds. Investors paid income tax on taxable bonds, but firms covered income tax on investors' behalf on tax-exempt bonds. Using a unique data-set of these...

Market index and individual stock returns exhibit jumps in addition to normal shocks. Equities have exposure to the market and sensitivity to the market is important for explaining equity returns and option prices. I develop a new factor model that explores (i) if a separate beta for market...

When the pricing kernel is U-shaped, then expected returns of claims with payout on the upside are negative for strikes beyond a threshold, determined by the slope of the U-shaped kernel in its increasing region, and have negative partial derivative with respect to strike in the increasing...

Numerous studies find S-shaped pricing kernels, which is conflicting with standard theory. In contrast to that, based on a novel GARCH model with structural breaks, I show that the pricing kernel is consistently U-shaped. The results are robust to variations in the methodology and hold for...

We use simultaneous data from equity, index and option markets in order to estimate a single-factor market model in which idiosyncratic volatility is allowed to be priced. We model the index dynamics' physical distribution as a mean-reverting stochastic volatility process as in Heston (1993),...