currently I am writing my Master-Thesis about SRI-Fonds. For analysing Sharpe Ratios from different Fonds I need to use the risk free rate (e.g. Euribor 3M). Unfortunately I can‘t find anything about dealing with negative risk free rates. Is it useful to calculate with those negative rates or should I prefer a risk free rate about 0% in case it‘s negative?
Thanks a lot for your answers. Maybe someone had the same problem before...