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.
Bollinger Bands plot a moving average with upper and lower bands set at 2 standard deviations, expanding during high volatility and contracting during low volatility to create actionable squeeze and breakout signals. The Bollinger Squeeze is especially powerful when combined with <a href="/academy/indicators/keltner-channels" class="text-primary hover:underline">Keltner Channels</a> in the TTM Squeeze setup, a favourite of professional traders. Pair Bollinger Bands with the <a href="/academy/indicators/rsi" class="text-primary hover:underline">RSI</a> to filter false signals and confirm <a href="/guides/trade-breakouts" class="text-primary hover:underline">breakout entries</a>. Set them up on <a href="/tools/platforms/tradingview" class="text-primary hover:underline">TradingView</a> for real-time alerts and multi-timeframe analysis.
Price Envelopes plot fixed percentage bands above and below a <a href="/academy/indicators/simple-moving-average" class="text-primary hover:underline">Simple Moving Average</a>, creating a straightforward volatility channel for identifying overextended price moves and potential reversal zones. They are among the simplest band indicators available and work well in ranging <a href="/market/forex" class="text-primary hover:underline">forex</a> and <a href="/market/stocks" class="text-primary hover:underline">stock</a> markets. Compare Price Envelopes with <a href="/academy/indicators/bollinger-bands" class="text-primary hover:underline">Bollinger Bands</a> in our <a href="/academy/indicators" class="text-primary hover:underline">indicator guide library</a> to decide which suits your style.
Chaikin Volatility measures the rate of change of the difference between high and low prices, providing a unique view of how the trading range is expanding or contracting. Unlike <a href="/academy/indicators/atr" class="text-primary hover:underline">ATR</a>, which smooths absolute range, Chaikin Volatility focuses on the acceleration of range changes. It is useful in <a href="/market/stocks" class="text-primary hover:underline">stock</a> and <a href="/market/forex" class="text-primary hover:underline">forex</a> markets and can be explored alongside other volatility tools in our <a href="/academy/indicators" class="text-primary hover:underline">indicator guide library</a>.
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.