nutsneal
to make it short: i do not want to enter a discussion about the most widely spread single figure among the professional alternative investment scene. i am aware of the ifs and whens, the improvements here and there. i think it is important to combine return and risk in one figure. for me sharpe is a quite good concept to do so. (sorry if i am doing you wrong, but i had conversations about the value of SR before - and this thread was not started out of the intention to have another one ...).
erik
i think after forty or fifty observations (=about five years if you use monthly data) all annualised standard deviations will be more or less the same, thus the sharpe ratios will be the same, whether you calculate them on five years daily data or five years monthly data.
having said that i remember another thread here that shed some light on the fact that you must go intraday to value a strategy, if the average holding period is just a few hours. i am still not sure about the argument ...
peace