U.S. exchange-traded stock options are exercisable before expiration. While put options should frequently be exercised early to earn interest, they are not. In this paper, we explain an early exercise decision rule and then examine actual exercise behavior during the period January 1996 through...

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...

Spreads of agency mortgage-backed securities (MBS) vary significantly in the cross section and over time, but the sources of this variation are not well understood. We document that, in the cross section, MBS spreads adjusted for the prepayment option show a pronounced smile with respect to 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...

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...