  The spin-polarized ferromagnetic state of a cold Fermi gas is investigated
for interacting and non-interacting charge-neutral and $\beta$-equilibrated
gases. The standard minimal couplings between the magnetic field and the
fermions' charges and magnetic dipole moments define the fermions' interaction
with the magnetic field. Assuming a variable coupling strength between the
magnetic field and the fermion (baryon) dipole moments, it is shown that a
ferromagnetized state can be achieved that corresponds to a lower energy
spin-polarized state with a magnetic field entirely due to the gas's magnetic
response. We find that, depending on the density, a very large increase in the
baryon dipole moments is needed to achieve this ferromagnetized state. While
the required increase seems unlikely, the induced magnetic field is of the
order $\sim10^{17}$ gauss. Furthermore, while externally magnetized Fermi gases
have an anisotropic pressure, the pressure of the ferromagnetized gas is
completely isotropic and the thermodynamically preferred magnetized state.
