Leading vs. Lagging Indicators
The distinction between indicators that confirm a trend after it's developed (lagging) and those that attempt to anticipate a change before it's confirmed (leading).
A lagging indicator, such as a moving average, confirms a trend after it has already developed, since it's built entirely from past price data by construction — it cannot, by its own mathematical nature, know about a trend before enough data exists to calculate it.
An indicator commonly labeled "leading," such as a bounded oscillator like RSI or Stochastic, is designed to turn earlier within a given price move than a lagging indicator would, but it's still built entirely from past data too — not a genuine forecast of the future. See Kaavon's dedicated Leading vs. Lagging Indicators article for why this structural trade-off exists and why combining both types is a standard practice.
Examples
- A moving-average crossover is a classic lagging signal, confirming a trend change only after enough new price data has accumulated.
- Pairing a faster-reacting oscillator with a slower-confirming trend indicator is a common, standard practice specifically because the two trade off early signal against reliable confirmation.