Module 4: Technical Analysis for Crypto
Volatility Indicators: Bollinger Bands and ATR
Chapter 11 of 16 · about 6 minutes
11.1 The calm before the storm
For two weeks, Bitcoin barely moved. Daily candles were small, and traders on social media complained that the market was boring.
"Enjoy the quiet," Hash said. "Quiet periods in crypto rarely last. Volatility moves in cycles: calm, then explosive, then calm again. Volatility indicators help you notice when the calm is getting unusually tight."
Module 1, Chapter 13 explained why crypto is volatile. This chapter introduces two tools that measure volatility on the chart: Bollinger Bands and the Average True Range.
11.2 Bollinger Bands
Bollinger Bands place a band above and below a moving average. The width of the band depends on how volatile price has been.
The standard settings:
| Component | Calculation |
|---|---|
| Middle band | 20-period SMA |
| Upper band | Middle band + 2 standard deviations |
| Lower band | Middle band − 2 standard deviations |
Standard deviation measures how spread out prices have been around their average. When prices swing widely, standard deviation is large, and the bands widen. When prices are calm, standard deviation is small, and the bands narrow.
| Example value | |
|---|---|
| 20-day SMA (middle band) | $100,000 |
| Standard deviation | $2,500 |
| Upper band | $100,000 + (2 × $2,500) = $105,000 |
| Lower band | $100,000 − (2 × $2,500) = $95,000 |
| Band width as % of middle | $10,000 ÷ $100,000 = 10% |
11.3 Reading the bands
The squeeze. When the bands narrow sharply, volatility is unusually low. This often precedes a large move. The squeeze doesn't tell you the direction, only that a bigger move may be coming.
| Period | Band width (illustrative) | Interpretation |
|---|---|---|
| Normal | 10 to 15% | Typical volatility |
| Squeeze | 4% | Volatility unusually compressed; a large move may follow |
| Expansion | 20%+ | A strong move is underway |
Chapter 11 · The Bollinger squeeze
A price line moves between an upper and a lower Bollinger Band, two standard deviations either side of a dashed 20-period moving average, with the space between the bands shaded. In the normal phase the bands are about 10 to 15% apart and price swings between them. In the squeeze the bands narrow to about 4%, marked with arrows pinching in and a note that the direction of the next move is unknown. In the expansion phase price breaks out and rides the upper band while the bands widen to 20% or more.
Riding the band. In strong trends, price can "walk" along the upper band for days or weeks. Just like RSI being overbought (Chapter 9), touching the upper band doesn't mean price must fall. In a strong uptrend, it's a sign of strength.
Mean reversion in ranges. In sideways markets, price tends to move between the bands, and touches of the outer bands are more likely to reverse toward the middle.
The middle band as support or resistance. In an uptrend, pullbacks often find support near the middle band (the 20 SMA). In a downtrend, rallies often stall there.
"So Bollinger Bands work like moving averages and volatility measures at the same time," said Mint.
"Exactly," said Hash. "And like the other tools, how you read them depends on whether the market is trending or ranging."
11.4 Average True Range
The Average True Range (ATR) measures how much an asset typically moves in a period. It doesn't show direction. It just tells you the size of a typical candle's range, including gaps.
Chapter 11 · True range
An illustrative example. A previous up candle closes at $99,000. The current up candle gaps higher, with a low of $100,000 and a high of $102,000. Three distances are measured: high minus low is $2,000; high minus the previous close is $3,000; and low minus the previous close is $1,000. The largest, $3,000, is highlighted as the true range. The ATR averages this value over 14 periods.
The true range of a period is the largest of three values:
- Today's high minus today's low.
- The distance from yesterday's close to today's high.
- The distance from yesterday's close to today's low.
The ATR is the average of the true range over a set number of periods, usually 14.
| Value | |
|---|---|
| Bitcoin 14-day ATR (illustrative) | $2,000 |
| Meaning | On an average day, Bitcoin's range has been about $2,000 |
Because crypto trades continuously, gaps between one candle's close and the next one's open are rare on most charts. So in crypto, ATR is mostly driven by each candle's high-low range.
11.5 Using ATR for stop-losses
ATR's most practical use is setting stop-losses that respect normal volatility.
A common mistake is setting a stop too close. If Bitcoin normally moves $2,000 a day, a stop $500 below your entry will likely get hit by ordinary noise, even if your idea was correct.
Many traders place stops at a multiple of ATR away from their entry, such as 1.5 or 2 times ATR, combined with support and resistance levels.
| Value | |
|---|---|
| Entry | $100,000 |
| ATR | $2,000 |
| Stop at 1.5 × ATR | $100,000 − $3,000 = $97,000 |
If $97,000 also sits just below a support zone, even better. The stop is outside both normal noise and the level where the trade idea would be wrong.
11.6 ATR for comparing assets and adjusting size
ATR also helps compare volatility across assets, as a percentage of price.
| Asset | Price | ATR | ATR as % of price |
|---|---|---|---|
| Bitcoin | $100,000 | $2,000 | 2% |
| A mid-sized token | $10 | $0.60 | 6% |
The smaller token moves three times as much, in percentage terms, on a typical day. If you used the same position size in both, your risk in the smaller token would be about three times higher. Chapter 16 shows how to use this to size positions so that each trade carries similar risk.
11.7 Volatility in crypto
Some volatility patterns are particularly relevant to crypto:
Volatility clusters. Calm periods tend to follow calm periods, and volatile periods follow volatile ones, until they switch.
Weekend compression. Weekends often have lower volume and narrower ranges, though sharp moves can still happen on thin liquidity.
Leverage-driven expansion. When volatility breaks out of a squeeze, liquidation cascades can make the move larger and faster than it would otherwise be.
Event volatility. Major economic announcements, regulatory decisions, and ETF flows can trigger volatility spikes.
11.8 Node's question
"So these tools tell me volatility is coming, but not which way," Node said. "What good is that?"
"More than you'd think," said Hash. "It tells you when to pay attention, how wide your stops need to be, how big your positions should be, and when a breakout might be real. Direction comes from trend, structure, and levels. Volatility tells you how to manage the trade."
11.9 Try it yourself
Add Bollinger Bands to a daily Bitcoin chart and find the three narrowest squeezes of the last year. Note what happened in the week after each one. Then add a 14-day ATR and note its current value. Calculate where a 1.5 × ATR stop would be below today's price, and check whether a support zone sits nearby.
Key takeaways from this chapter
- Volatility moves in cycles; calm periods often precede large moves.
- Bollinger Bands use a 20-period SMA with bands two standard deviations above and below.
- A Bollinger squeeze signals unusually low volatility and a possible large move, but not its direction.
- Price can ride the outer bands in strong trends; outer band touches are more likely to reverse in ranges.
- ATR measures the typical size of price movement, regardless of direction.
- ATR helps set stops outside normal noise and compare volatility across assets.
- Volatility tools help you manage trades: when to watch, where to place stops, and how big to trade.