Suppose Rf is 5% and Rm is 10%. According to the SML and the CAPM, an asset with a beta of -2.0 has a required return of negative 5% [= 5 - 2(10 - 5)]. Can this be possible? Does this mean that the asset has negative risk? Can you describe why anyone would ever invest in an asset that has an expected and required return that is negative?