Standard Deviation (SDV)

SDV(Vector, Periods, Standard Deviations, MA Type)

Overview
Standard Deviation is a common statistical calculation that measures volatility. The SDV function computes the volatility the same way as the Bollinger Bands, which is a rolling average of the standard deviation.

Interpretation
Major highs and lows often accompany extreme volatility. High values of standard deviations indicate that the price or indicator is more volatile than usual.

Recommended Parameters
Vector: CLOSE
Periods: 21
Standard Deviations: 2
MA Type: SIMPLE

Example
set SDV21 = SDV(CLOSE, 21, 2, SIMPLE)
set BUY = SDV21 > REF(SDV21, 10)
Evaluates to true when 21 period Standard Deviations are greater than 10 days ago.