What Are Bollinger Bands?
Bollinger Bands are a volatility indicator developed by John Bollinger in the 1980s. They consist of three lines plotted on a price chart: a middle band (simple moving average) and two outer bands that represent standard deviations from that average.
Bollinger Bands dynamically expand and contract based on market volatility, making them incredibly useful for identifying overbought/oversold conditions, potential breakouts, and trend strength.
Core Concept: Bollinger Bands show the relationship between price and volatility. When bands narrow (low volatility), an explosive move often follows. When bands widen (high volatility), a period of consolidation typically comes next.
Understanding the Three Components
1. Middle Band (20-period SMA)
- Simple moving average, typically set to 20 periods
- Acts as dynamic support/resistance
- Represents the "fair value" or mean price
- Price tends to revert to this middle band
2. Upper Band (Middle Band + 2 Standard Deviations)
- Set 2 standard deviations above the middle band
- Acts as dynamic resistance in normal markets
- Price touching upper band can signal overbought conditions
- In strong uptrends, price can "walk the band"
3. Lower Band (Middle Band - 2 Standard Deviations)
- Set 2 standard deviations below the middle band
- Acts as dynamic support in normal markets
- Price touching lower band can signal oversold conditions
- In strong downtrends, price can "walk" the lower band
Bollinger Band Settings
Standard Settings (20, 2)
The default and most commonly used settings:
- Period: 20 (middle band)
- Standard Deviation: 2
- Best for: Daily charts, swing trading
- Statistical fact: 95% of price action occurs within 2 standard deviations
Alternative Settings for Different Trading Styles
| Trading Style |
Recommended Settings |
Why |
| Scalping (1-5 min) |
(12, 2) or (10, 1.5) |
More sensitive, catches quick moves |
| Day Trading |
(20, 2) standard |
Balanced sensitivity and reliability |
| Swing Trading |
(20, 2) or (50, 2.5) |
Filters noise, catches major swings |
| Long-term |
(50, 2.5) |
Identifies major trend changes |
The Bollinger Squeeze: High-Probability Setup
The Bollinger Squeeze is one of the most powerful patterns—it predicts explosive breakouts.
What Is a Bollinger Squeeze?
- Occurs when bands contract to their narrowest range
- Indicates extremely low volatility
- Signals that a significant move is imminent
- Key principle: Low volatility followed by high volatility (market cycles)
How to Trade the Bollinger Squeeze
- Identify the squeeze: Bands narrower than they've been in 6 months
- Wait for breakout: Strong candle closes outside the bands
- Confirm direction: Volume should increase on breakout
- Entry: Enter in the direction of the breakout
- Stop loss: Opposite side of the squeeze range
- Target: Measure squeeze width and project from breakout point
Bollinger Squeeze Breakout Example
Asset: AAPL (Daily chart)
Squeeze setup: Stock consolidates for 3 weeks, Bollinger Bands narrow from $10 width to $3 width
Breakout: Strong green candle closes at $152, above upper band, with 3x average volume
Entry: $153 (above breakout candle)
Stop loss: $147 (below squeeze low)
Target: $165 (squeeze range of $6 projected upward)
Result: Stock rallied to $168 over 8 days
Mean Reversion Strategy (Bounce)
In ranging markets, Bollinger Bands act as dynamic support and resistance for mean-reversion trades.
Trading the Bollinger Bounce
Buy Setup (Bounce from Lower Band)
- Condition: Price touches or penetrates lower band
- Market context: Ranging market (not strong downtrend)
- Confirmation: Bullish reversal candlestick (hammer, engulfing)
- Entry: When price closes back inside the bands
- Target: Middle band (20 SMA) or upper band
- Stop loss: Below the lower band touch point
Sell Setup (Rejection from Upper Band)
- Condition: Price touches or penetrates upper band
- Market context: Ranging market (not strong uptrend)
- Confirmation: Bearish reversal candlestick (shooting star, bearish engulfing)
- Entry: When price closes back inside the bands
- Target: Middle band (20 SMA) or lower band
- Stop loss: Above the upper band touch point
Critical Rule: Mean reversion only works in ranging markets. In strong trends, price "walks the band" and bounce trades will fail. Always check trend context first.
Trend-Following Strategy (Walking the Band)
In strong trends, price consistently stays near one band—this is called "walking the band."
Bullish Band Walk
- Characteristic: Price repeatedly touches upper band without significant pullback
- Meaning: Very strong uptrend, buyers in complete control
- Trading strategy: Buy pullbacks to middle band (20 SMA)
- Entry trigger: Price bounces off middle band with bullish candle
- Stop: Close below middle band
- Target: Previous high or new upper band touch
Bearish Band Walk
- Characteristic: Price repeatedly touches lower band without significant rally
- Meaning: Very strong downtrend, sellers in complete control
- Trading strategy: Sell rallies to middle band (20 SMA)
- Entry trigger: Price rejected from middle band with bearish candle
- Stop: Close above middle band
- Target: Previous low or new lower band touch
Double Bottom/Top with Bollinger Bands
A powerful reversal pattern unique to Bollinger Band analysis.
W-Bottom (Bullish Reversal)
- First low touches or breaks lower band (selling climax)
- Price rallies back toward middle band
- Second low forms ABOVE lower band and higher than first low
- Price breaks above middle band = buy signal
- Confirmation: Second low shows strength (doesn't reach band)
- Entry: Break above middle band or previous swing high
M-Top (Bearish Reversal)
- First high touches or breaks upper band (buying climax)
- Price pulls back toward middle band
- Second high forms BELOW upper band and lower than first high
- Price breaks below middle band = sell signal
- Confirmation: Second high shows weakness (can't reach band)
- Entry: Break below middle band or previous swing low
Combining Bollinger Bands with Other Indicators
Bollinger Bands + RSI
Powerful combination for identifying high-probability reversals:
- Bullish setup: Price at lower band + RSI below 30 (oversold)
- Bearish setup: Price at upper band + RSI above 70 (overbought)
- Confirmation: RSI divergence strengthens signal
- Entry: Wait for both indicators to confirm reversal
Bollinger Bands + MACD
Great for trend confirmation and timing:
- Trend start: Bollinger squeeze + MACD crossover = breakout trade
- Trend continuation: Price at middle band + MACD histogram rising = buy dip
- Trend exhaustion: Price walks band but MACD diverges = exit signal
Bollinger Bands + Volume
Volume validates Bollinger Band signals:
| Signal |
Volume Pattern |
Reliability |
| Squeeze breakout |
High volume (2x+ average) |
Very high |
| Band touch |
Declining volume |
Reversal likely |
| Middle band bounce |
Increasing volume |
Trend continuation likely |
| Band walk |
Steady/rising volume |
Strong trend confirmed |
Common Bollinger Band Mistakes
1. Shorting/Buying Just Because Price Touches a Band
- Mistake: Assuming price touching upper band means "sell" automatically
- Reality: In trends, price walks the band for extended periods
- Solution: Check trend direction first; only fade the bands in ranging markets
2. Using Bollinger Bands Alone
- Mistake: Trading bands without context from other indicators
- Reality: Bands show volatility and price relative to mean, not direction
- Solution: Combine with RSI, MACD, or trend indicators for confirmation
3. Ignoring Market Context
- Bollinger Bands behave differently in trending vs. ranging markets
- Always identify market regime before applying strategy
- Trending: Use band walks and middle band bounces
- Ranging: Use band touches for mean reversion
4. Not Waiting for Squeeze Confirmation
- Bands can stay narrow for extended periods before breaking out
- Don't enter before clear directional breakout occurs
- Always wait for volume confirmation on breakout
Advanced Bollinger Band Techniques
The %B Indicator
Measures where price is relative to the bands:
- %B = 1.0: Price at upper band
- %B = 0.5: Price at middle band
- %B = 0.0: Price at lower band
- %B > 1.0: Price above upper band (very strong)
- %B < 0.0: Price below lower band (very weak)
- Use: Identify extreme overbought/oversold conditions
Bandwidth Indicator
Measures the width between upper and lower bands:
- Narrow bandwidth: Low volatility, squeeze forming
- Wide bandwidth: High volatility, potential exhaustion
- Strategy: Trade breakouts when bandwidth hits multi-month lows
- Exit signal: Bandwidth expansion slows = trend exhaustion
Complete Bollinger Band Trading Plan
Pre-Trade Checklist
- ✓ Identify market regime (trending or ranging)
- ✓ Check for Bollinger squeeze or normal volatility conditions
- ✓ Confirm with additional indicator (RSI, MACD, volume)
- ✓ Identify clear support/resistance levels
- ✓ Determine entry, stop loss, and target before entering
- ✓ Ensure minimum 2:1 risk/reward ratio
Risk Management Rules
- Risk maximum 1-2% of capital per trade
- Place stops beyond band extremes, not at exact band levels
- Scale out of positions as price reaches bands
- Tighten stops when price fails to make new band touches in trends
Key Takeaways
- Bollinger Bands measure volatility and identify overbought/oversold extremes
- The Bollinger Squeeze predicts explosive breakouts from low-volatility periods
- Mean reversion works in ranging markets; trend-following works in trending markets
- Never assume touching a band means automatic reversal—check trend context
- Walking the band indicates very strong trending conditions
- W-bottoms and M-tops provide high-probability reversal signals
- Combine Bollinger Bands with RSI, MACD, or volume for better confirmation
- Use %B and Bandwidth indicators for additional insights
- Always wait for confirmation before entering squeeze breakout trades
- Adjust settings based on timeframe and trading style
Master Tip: The most profitable Bollinger Band traders don't use the bands alone. They combine them with trend analysis, volume, and complementary indicators to create a complete trading system with clear rules for entry, exit, and risk management.
Next Steps
Enhance your Bollinger Band trading by learning:
- Moving averages to better understand the middle band's significance
- RSI for powerful overbought/oversold confirmation
- Volume analysis to validate breakout signals
- Support and resistance to set better profit targets