39 citations · 39 across the 3 of their papers we have counts for
5 papers
Bubbles, convexity and the Black--Scholes equation
Erik Ekström, Johan Tysk
A bubble is characterized by the presence of an underlying asset whose discounted price process is a strict local martingale under the pricing measure. In such markets, many standa…
Convexity theory for the term structure equation
Erik Ekstrom, Johan Tysk
We study convexity and monotonicity properties for prices of bonds and bond options when the short rate is modeled by a diffusion process. We provide conditions under which convexi…
Convexity preserving jump-diffusion models for option pricing
Erik Ekström, Johan Tysk
We investigate which jump-diffusion models are convexity preserving. The study of convexity preserving models is motivated by monotonicity results for such models in the volatility…
A boundary point lemma for Black-Scholes type operators
Erik Ekström, Johan Tysk
We prove a sharp version of the Hopf boundary point lemma for Black-Scholes type equations. We also investigate the existence and the regularity of the spatial derivative of the so…
Properties of option prices in models with jumps
Erik Ekström, Johan Tysk
We study convexity and monotonicity properties of option prices in a model with jumps using the fact that these prices satisfy certain parabolic integro-differential equations. Con…