Negative magnetic susceptibility is exhibited by

Magnetic susceptibility $\chi$ is defined as the ratio of the intensity of magnetization $M$ to the magnetic intensity $H$.

For diamagnetic materials, the induced magnetization is in the direction opposite to the applied magnetic field. Therefore, they have a small and negative magnetic susceptibility ($-1 \le \chi < 0$).

For paramagnetic materials, the susceptibility is small and positive ($\chi > 0$).

For ferromagnetic materials, the susceptibility is large and positive ($\chi \gg 1$).

Thus, negative magnetic susceptibility is exhibited by diamagnetic materials only.