Speyer's positivity conjecture for matroid g-polynomials

Let $\mathsf{M}$ be a matroid, and let $g_{\mathsf{M}}(t)$ denote its $g$-polynomial. g-polynomial positivity conjecture. The polynomial $g_{\mathsf{M}}(t)$ has positive coefficients. This is presented as a related conjecture of Speyer and remains unresolved in the supplied text.