This paper introduces bootstrap specification tests for diffusion processes. In the one-dimensional case, the proposed test is closest to the nonparametric test introduced by Ait-Sahalia (1996), in the sense that both procedures determine whether the drift and variance components of a particular...

The so-called leverage hypothesis is that negative shocks to prices/ returns affect volatility more than equal positive shocks. Whether this is attributable to changing financial leverage is still subject to dispute but the terminology is in wide use. There are many tests of the leverage...