Also called the line of destiny, the fate line is read as your relationship to direction — career, calling, and the degree to which your path has felt chosen versus assigned. It is the most variable of the four, and the most commonly absent.
No fate line is a perfectly ordinary result and is read as a life that resists a single track: freelancers, career-changers, and people whose work is genuinely their own invention. It is read as self-direction, not aimlessness.
Where it begins is the useful detail. Starting low, near the wrist, is read as an early and clear sense of direction. Starting higher up the palm is read as finding your path later — the tradition puts this around the early thirties, which is roughly when most people report it happening anyway.