Two effects largely define the evolution of spatial bias:
Statistical (Peak) Bias. Dominates the bias at high redshifts. Produces Positive Bias (b>1). Strong dependence on mass of galaxies. Bias decreases with decreasing redshift.
Pair-wise Velocity bias (bv =0.5-0.6) reflects mainly the spatial (anti)bias. It does NOT mean that galaxies move slower than the dark matter.
Galaxies in clusters move slightly faster
(b =1.1-1.3) than DM particles