The authors test for the presence of long memory in daily stock returns and their squares using a robust semiparametric procedure of I. Lobato and P. M. Robinson (1997). Spurious results can be produced by nonstationarity and aggregation. The authors address these problems by analyzing...

This article investigates the finite-sample performance of a modified Box-Pierce Q statistic (Q*) for testing that financial time series are uncorrelated without assuming statistical independence. The finite-sample rejection probabilities of the Q* test under the null and its power are examined...