Horizon matters: why the edge lives at a month, not intraday

Not every idea fails because it's bad; many fail because they're fast. At intraday or few-day scale, noise and cost dominate any weak pattern.

In our tests, the minimum horizon with real edge is around a month, and the sweet spot is one to three months. There you trade less, cost weighs less, and ranking signals have room to express themselves.

The lesson: before optimizing parameters, choose the horizon well. It's the decision that most changes whether a strategy has a future.