Large scale structure contains vastly more Fourier modes than the CMB, and is therefore a promising arena for studying the early universe. One obstacle to using these modes is the non-linearity of structure formation. The amount of weakly coupled information available is therefore very sensitive to scale at which non-linear effects become important and simulations become necessary. Using effective field theory techniques, I will present evidence that the perturbative description of dark matter is much better behaved than previously thought. I will discuss the implications for improving constraints on non-gaussian initial conditions.