When you strip the noise away, the real question is simple: signal half-life matters as much as signal direction. Mechanism: A signal that points the right way but decays quickly should not be traded with the same holding period as a slow structural signal. $$ Signal\ Value_t = Signal_0 \cdot e^{-\lambda t} $$ Plain English: Some signals lose explanatory power quickly, so old information should get less weight. Why it matters: Time is part of the thesis. If the horizon changes, the execution logic should change with it. Market translation: A short-horizon mean reversion signal on $QQQ is a different object from a medium-term trend-following process on the same ETF. Failure mode: The expensive error is mixing a fast entry logic with a slow stop and calling the result "conviction." Review question: Before sizing up, identify whether the edge comes from cash flow, volatility, timing or balance-sheet structure. A lot of confusion disappears once you separate the headline from the mechanism.