[iabacu]

Your current company will promote (and compensate) you based on your performance in the past cycles.

Your new company will offer you a level (and compensation) based on your expected performance in future cycles.

If you're on a growth trajectory, jumping jobs will usually give you a bump because your new company treats you differently than your current company. And it doesn't matter much whether you're coming from company A to B, or from B to A!