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Volatility Indicators

Volatility indicators tell you about risk and opportunity. High volatility means bigger potential gains but also bigger potential losses.

Bollinger Bands

What it is: A volatility channel around a moving average (typically 20-period SMA ± 2 standard deviations).

Components

ComponentCalculationPurpose
Upper BandSMA + (2 × StdDev)Resistance
Middle Band20-period SMAMean
Lower BandSMA - (2 × StdDev)Support

Signals

PRICE AT UPPER BAND: Potentially overbought
→ May pull back to middle band
→ Score: +1.5 bearish

PRICE AT LOWER BAND: Potentially oversold
→ May bounce to middle band
→ Score: +1.5 bullish

BOLLINGER SQUEEZE: Bands narrow significantly
→ Low volatility, big move coming
→ Score: Alert (no direction bias)

Bandwidth

Bandwidth measures how wide the bands are:

Bandwidth = ((Upper - Lower) / Middle) × 100
BandwidthVolatilityImplication
< 10%Very lowSqueeze - big move coming
10-20%NormalStandard conditions
> 20%HighVolatile, use smaller positions

Trading the Squeeze

When bandwidth drops below 10%, a big move is coming. The direction is unknown, but you can prepare:

  1. Watch for breakout above upper band (bullish)
  2. Watch for breakdown below lower band (bearish)
  3. Use other indicators to confirm direction

Best for: Identifying price extremes and volatility conditions


ATR (Average True Range)

What it is: Measures volatility by calculating the average range between high and low prices.

Calculation

True Range = MAX of:
- Current High - Current Low
- |Current High - Previous Close|
- |Current Low - Previous Close|

ATR = Average of True Range over N periods (typically 14)

Uses

1. Position Sizing

Higher ATR = More volatile = Smaller position

Position Size = Risk Amount / ATR

Example:
Risk Amount: $500
ATR: $2.50
Position Size: 200 shares

2. Stop-Loss Placement

Stop TypeCalculationUse Case
TightPrice - (1 × ATR)Scalping
NormalPrice - (2 × ATR)Swing trading
WidePrice - (3 × ATR)Position trading
Example:
Entry Price: $100
ATR: $3

Tight Stop: $97 (1 ATR)
Normal Stop: $94 (2 ATR)
Wide Stop: $91 (3 ATR)

3. Volatility Assessment

ATR % of PriceVolatility Level
> 5%Very high
3-5%High
1-3%Normal
< 1%Low

ATR in Our System

We provide suggested stop-loss levels based on ATR:

{
"atr": 2.45,
"atrPercent": 2.1,
"volatility": "normal",
"suggestedStops": {
"tight": 115.55, // 1x ATR
"normal": 113.10, // 2x ATR
"wide": 110.65 // 3x ATR
}
}

Best for: Position sizing, stop-loss placement, and volatility-adjusted risk management


Volatility-Based Position Sizing

Combine ATR with your risk tolerance:

Step 1: Determine your risk per trade (e.g., 2% of portfolio)
Step 2: Calculate dollar risk = Portfolio × 0.02
Step 3: Calculate shares = Dollar Risk / (2 × ATR)
Step 4: Calculate position size = Shares × Entry Price

Example

Portfolio: $100,000
Risk per trade: 2% = $2,000
Entry Price: $50
ATR: $2.50
Stop-Loss: 2 × ATR = $5

Shares = $2,000 / $5 = 400 shares
Position Size = 400 × $50 = $20,000

This ensures you never lose more than 2% on any single trade, regardless of the stock's volatility.


Summary Table

IndicatorSignal TypeBullish ScoreBearish Score
BBands OversoldExtreme+1.5-
BBands OverboughtExtreme-+1.5
Bollinger SqueezeAlert--

Note: ATR doesn't generate buy/sell signals directly. Instead, it's used for:

  • Position sizing
  • Stop-loss placement
  • Risk management

Next: Volume Indicators