This paper reviews the recent developments in the field of the variance-ratio (VR) tests of the random walk and martingale hypothesis. In particular, we present the conventional individual and multiple VR tests as well as their improved modifications based on power-transformed statistics, rank...

This study examines the random walk hypothesis for the Shanghai and Shenzhen stock markets for both A and B shares, using daily data over the period 1992-2007. The hypothesis is tested with new multiple variance ratio tests - Whang-Kim subsampling and Kim's wild bootstrap tests - as well as the...