Standard Deviation measures the dispersion of closing prices from their mean over a given period, providing the mathematical foundation for Bollinger Bands and many other volatility tools. Rising standard deviation signals increasing volatility across stocks, crypto, and forex. Review our indicator guide library to see how standard deviation powers multiple volatility-based trading tools.
Standard Deviation = √[Σ(Close − Mean)² / N] over N periods. Low readings indicate price is clustered tightly around the mean (calm); high readings indicate price is widely dispersed (volatile). It is commonly plotted as a separate indicator below price.
The Mass Index identifies potential trend reversals by measuring the narrowing and widening of the range between high and low prices, generating a "reversal bulge" signal when the range first expands then contracts. It is a unique contrarian tool for <a href="/market/stocks" class="text-primary hover:underline">stock</a> and <a href="/market/forex" class="text-primary hover:underline">forex</a> traders. Combine Mass Index reversal signals with momentum tools from our <a href="/academy/indicators" class="text-primary hover:underline">indicator guide library</a> for higher-probability entries.
Donchian Channels plot the highest high and lowest low over a specified period, forming a simple but effective volatility envelope and breakout system that powered the legendary Turtle Trading strategy. They are widely used in <a href="/market/forex" class="text-primary hover:underline">forex</a> and <a href="/market/crypto" class="text-primary hover:underline">crypto</a> for trend-following breakout <a href="/strategies" class="text-primary hover:underline">strategies</a>. Compare Donchian Channels with <a href="/academy/indicators/bollinger-bands" class="text-primary hover:underline">Bollinger Bands</a> and <a href="/academy/indicators/keltner-channels" class="text-primary hover:underline">Keltner Channels</a> in our <a href="/academy/indicators" class="text-primary hover:underline">indicator guide library</a>.
Keltner Channels plot an EMA with upper and lower bands based on <a href="/academy/indicators/atr" class="text-primary hover:underline">ATR</a>, producing smoother envelopes than <a href="/academy/indicators/bollinger-bands" class="text-primary hover:underline">Bollinger Bands</a> — and the two are frequently used together for the TTM Squeeze setup. This combination identifies low-volatility compression zones that precede explosive <a href="/guides/trade-breakouts" class="text-primary hover:underline">breakout</a> moves in any market. Apply Keltner Channels on <a href="/tools/platforms/tradingview" class="text-primary hover:underline">TradingView</a> and overlay Bollinger Bands to spot squeeze conditions with a single glance.
ATR measures market volatility by calculating the average range of price bars over a specified period — it is essential for position sizing, stop-loss placement, and identifying volatility shifts. Use our <a href="/tools/calculators/position-size-calculator" class="text-primary hover:underline">position size calculator</a> to convert ATR readings into proper trade sizing instantly. Read the <a href="/guides/use-stop-loss-orders" class="text-primary hover:underline">stop-loss guide</a> and the <a href="/guides/calculate-position-size" class="text-primary hover:underline">position sizing guide</a> to master ATR-based risk management across every market. ATR adapts to any asset — apply it in <a href="/market/crypto" class="text-primary hover:underline">crypto</a>, <a href="/market/stocks" class="text-primary hover:underline">stocks</a>, and <a href="/market/forex" class="text-primary hover:underline">forex</a> for volatility-adjusted trading.