There is a natural action of a torus on a given moduli space of a quiver. Weist shows that the components of the fixed point locus of this action are again quiver moduli; more precisely moduli spaces for a covering quiver. The induced torus action on the tangent space of a fixed point induces a weight space decomposition. We show that the weight spaces can be identified with Ext groups of representations of the covering quiver. For actions of tori of rank one, we give an explicit description of attracting sets of fixed point components. The talk is based on joint work with M. Boos.