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 .
Depending on the parameters , the growth may be much faster than in a standard matter-dominated era .
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 .
We find that a lower limit to the baryon bias b > 0.5 requires the total effective parameter of state w _ { e } = 1 + p / \rho to be larger than 0.6 while a limit b > 0.73 would rule out the model .