- The difference between impulse and corrective movement, and how to tell them apart
- Why volatility contraction precedes expansion, and how to measure it
- How to read the character of a pullback
Price alternates between two states: expansion (directional, wide bars, rising volume) and contraction (sideways, narrowing bars, falling volume). Every setup in technical analysis is an attempt to be positioned at the end of a contraction, before the expansion.
Impulse versus correction
- SpeedImpulse (with the trend): Fast — covers ground in few barsCorrection (against it): Slow — takes many bars to cover less ground
- Bar characterImpulse (with the trend): Wide range, closes near extremesCorrection (against it): Narrow, overlapping, closes mid-range
- VolumeImpulse (with the trend): Elevated, expandingCorrection (against it): Declining
- OverlapImpulse (with the trend): Bars barely overlap — one-wayCorrection (against it): Heavy overlap — indecision
- ShapeImpulse (with the trend): Clean and steepCorrection (against it): Choppy, sideways drift or shallow angle
╱│ impulse
╱ │
┌────┐ ╱ │
╱ │coil│ ─────╱ │
╱ └────┘ │
╱│ ╱ contraction: │
╱ │ ╱ narrow bars, │
┌────┐ ╱ │ ╱ volume drying │
──╱│coil│──╱ ╲╱
╱ └────┘
╱
expansion → contraction → expansion → contraction → expansion
Money is made in the expansions. Positions are BUILT in the contractions. Volatility contraction, and why it precedes movement
Volatility is mean-reverting: quiet periods are followed by active ones and vice versa. This is one of the most robust empirical regularities in markets, and it has a mechanical explanation — as a range narrows, the population of participants willing to transact at those prices shrinks, so it takes less order flow to move price out of the range.
- ATR%
- average true range as a percentage of price — the typical daily swing
Each successive pullback inside the base gets shallower and quieter — the VCP shape.
- Pullback 1
- −18%week 1–4
- Pullback 2
- −11%week 5–8
- Pullback 3
- −6%week 9–11
- Pullback 4
- −3%week 12–13
- ATR% start vs now
- 4.1% → 1.9%
Reading the character of a pullback
- ✓Volume declines through the pullback
- ✓Bars narrow and overlap heavily
- ✓Holds above a prior structural low or a rising moving average
- ✓Takes longer in time than the advance did, but covers less ground
- ✓Retraces roughly a third to a half of the prior leg
- ✕Volume expands as price falls
- ✕Wide bars closing near their lows
- ✕Cuts straight through the prior swing low
- ✕Retraces most or all of the prior advance
- ✕Faster and more violent than the advance that preceded it
You will hear that pullbacks "should" retrace 38.2%, 50% or 61.8%. The Fibonacci framing is decoration; the useful part is the ordinary observation that shallow pullbacks indicate eager demand and deep ones indicate reluctance.
A trend whose pullbacks are getting progressively deeper is weakening, whatever ratio each one lands on. Track the sequence of retracement depths rather than trying to make each one hit a number.
Where price action reasoning fails
- Low liquidity. Bar character is meaningless when a handful of orders draws the bar. Every conclusion in this lesson assumes a genuinely traded instrument.
- Event-driven gaps. A result announcement or a regulatory shock overrides the rhythm entirely. Price action describes flow, and a shock is not flow.
- Range-bound markets. Impulse-and-correction logic assumes a trend exists. Inside a range, every leg looks like an impulse until it stops at the other edge.
- Hindsight labelling. It is trivial to mark impulses and corrections on a chart of the past. The discipline is to label them before the next bar — and to notice how often the label was wrong.
- ☐Expansion or contraction — which state is this instrument in right now?
- ☐If in a pullback: is volume declining and are bars narrowing?
- ☐Is each successive pullback shallower than the last, or deeper?
- ☐What is the ATR% now versus at the start of this consolidation?
- ☐Has the correction started behaving like an impulse? That's a character change.
In one screen
- 1Markets alternate between directional expansion and sideways contraction.
- 2Impulse is fast, wide and heavy-volume; correction is slow, overlapping and quiet.
- 3Volatility contraction precedes expansion — successively shallower pullbacks mean supply is drying up.
- 4A correction that starts behaving like an impulse has changed character, often before structure breaks.
Check yourself
Nothing is scored or stored — the explanation after each answer is the point.
A stock in an uptrend pulls back. Volume rises through the decline, bars are wide and close near their lows. How should this be classified?
Why do successively shallower pullbacks inside a base matter?