You're about right for static stability.
There are two different dynamic modes, the long period - commonly called the phugoid or sometimes "porpoising" typically with a period around half a minute in light aeroplanes, and the short period. They are driven by static stability, but the dynamic stability is down to damping terms. At first approximation I would tend to expect the phugoid to be stabilised at aft CG but the SPO to be destabilised, and vice-versa, but those are not universal rules.
G