Matstat seminarium fredagen 6 april kl. 13.15 i MH227 Hanspeter Schmidli, Försäkringsmatematisk Laboratorium, Köpenhamn On minimising the ruin probability by investment and reinsurance We consider a classical risk model and allow investment into a risky asset modelled as a Black-Scholes model as well as (proportional) reinsurance. Via the Hamilton-Jacobi-Bellman approach we find a candidate for the optimal strategy. We prove a verification theorem in order to show that any increasing solution to the HJB equation is bounded and solves the optimisation problem. Finally we prove that an increasing solution to the HJB equation exists.