  In most models of dark energy the structure formation stops when the
accelerated expansion begins. In contrast, we show that the coupling of dark
energy to dark matter may induce the growth of perturbations even in the
accelerated regime. In particular, we show that this occurs in the models
proposed to solve the cosmic coincidence problem, in which the ratio of dark
energy to dark matter is constant. Moreover, if the dark energy couples only to
dark matter and not to baryons, as requested by the constraints imposed by
local gravity measurements, the baryon fluctuations develop a constant,
scale-independent, large-scale bias which is in principle directly observable.
