The statistics of dark matter halos bear the imprint of cosmological features such as the matter/energy balance of the Universe and its initial conditions. Halo counts and correlation properties may thus allow to measure the equation of state of Dark Energy, the amount of primordial non-Gaussianity, the mass of neutrinos and of Dark Matter particles. I will discuss some recent progress of the analytical predictions for the halo mass function and bias, and their comparison with simulations.