Semistability of Certain Bundles on Second Symmetric Power of a Curve

Let $C$ be a smooth irreducible projective curve and $E$ be a rank 2 stable vector bundle on $C$. Then one can associate a rank 4 vector bundle ${\mathcal{F}}_2(E)$ on $S^2(C)$, second symmetric power of $C$. Our goal in this article is to study semistability of this bundle.