Ratios that indicate the statistical significance of a fund's alpha typically appraise its performance. A growing literature suggests that even in the absence of any ability to predict returns, holding options positions on the benchmark assets or trading frequently can significantly enhance...

We examine the connection between discrete-time models of financial markets and the celebrated Black--Scholes--Merton (BSM) continuous-time model in which ''markets are complete." Suppose that (a) the probability law of a sequence of discrete-time models converges to the law of the BSM model and...