Navigation: Realtest Script Language > Syntax Element Details > SigSpike Category Indicator Functions Description Adam Grimes' Sigma Spike indicator Syntax SigSpike(len) Parameters len - lookback period Notes Sigma Spike is defined as ROC(C,1) / StdDev(ROC(C,1),len)[1]. Example Spike: SigSpike(100) Large negative values indicate a sharp downward price spike relative to recent volatility. Copyright © 2020-2026 Systematic Solutions, LLC