Denote Θ C as the Frobenius class of a curve C over the finite field Fq. In this paper we determine the expected value of Tr(Θ n C ) where C runs over all biquadratic curves when q is fixed and g tends to infinity. This extends work done by Rudnick [14] and Chinis [5] who separately looked at hyperelliptic curves and Bucur, Costa, David, Guerreiro and Lowry-Duda [1] who looked at ℓ-cyclic curves, for ℓ a prime, as well as cubic non-Galois curves.