Who this entry is for — The starting point of Chapter 2: why prices move the way they do. Hurst splits the motion into parts and says which part the trader can time.
Source: J. M. Hurst, The Profit Magic of Stock Transaction Timing, Prentice-Hall, 1970 — Chapter 2, Timing Is the Key (pp. 29–34).
Prerequisites
Chapter 1 (Hurst operating philosophy): you know what the method wants to achieve. Here you find out on what ground it can succeed.
Something unconventional is required
In plain words — "Buy low, sell high" is useless if you do not know what makes prices swing. Hurst adds a third cause beyond chance and fundamentals: a semi-predictable cyclic component.
Traditional approaches explain prices with only two causes: random events and fundamental factors. The former, by nature, cannot help prediction; the latter is a field "ploughed for years by competent people" — unlikely to yield the drastic timing improvement Chapter 1 demands. If help exists, Hurst writes, it must come from another quarter entirely — and will therefore be unconventional.
The chapter introduces this third cause and names it, with the honesty of the mathematician's unknown, "X motivation": on the why only theories exist, but that the effect exists and is usable "can be proven beyond all question" (the proof comes in Chapters 3, 9, 11 and the appendices — Chapter 2 defines).
The ten formal elements
In plain words — Ten numbered statements (I–X). The first five describe the whole of price motion; the other five — the five principles — govern the cyclic part.
The non-cyclic part (I–V)
| # | Element | Content |
|---|---|---|
| I | Random | Decisions unrelated to price weigh at most ~2% of the motion |
| II | Historical events | Wars, crises, headlines: negligible market impact |
| III | Foreseeable fundamentals | ~75% of the motion — a smooth, slow trend |
| IV | Unforeseeable fundamentals | Rare, but large and sudden: to be guarded against, not predicted |
| V | "X" motivation | ~23% of the motion — oscillatory and semi-predictable |
Element V deserves the original words:
"23% of all price motion is oscillatory in nature and semi-predictable!" (p. 31)
The cyclic part (VI–X)
Summation, commonality, variation, nominality, proportionality: they are the Five principles of the cyclic model, each with its own entry.
The book's example — The assassination of President Kennedy (November 1963): a quarter of an hour of panic, then the Dow climbs "in nearly unbroken manner" from the 710 area to the 1000 area. For Hurst it demonstrates element II: great events do not explain the systematic motion of prices.
The model "in homely terms"
In plain words — A slow trend with a dozen waves on top: the longer waves are also the taller ones, and each breathes slowly, changing magnitude and duration.
After the formal list Hurst restates the model qualitatively (p. 34), and it is worth following him: visualize a tendency changing slowly and smoothly on fundamentals; mix in, occasionally, a sharp move from unforeseen specific developments; conceive all this as about 75% of the motion, still generally smooth. Stir in a little random action. Superimpose the sum of 12 cyclic motions worth together about 23%, the longer elements being the larger, each slowly fluctuating in magnitude and duration. Let all of it influence human decision-making en masse: the resulting purchases and sales are the changing prices.
What the model does and does not do
| The model… | The model does not… |
|---|---|
| Explains why chart patterns exist (Ch. 3) | Guarantee perfect timing |
| Permits turning-point estimates, imperfect but useful | Replace risk management |
| Justifies purely "technical" analysis | Remove fundamentals from the underlying trend |
The declared expectation is about 10% wrong signals even at full skill — manageable with Chapter 5's protections, not removable.
Warning — The cyclic 23% is not "the whole chart": it is the part timing works on. The fundamental 75% remains the undercurrent steering the medium term — the envelope's centre line shows it at all times.
Summary card
| Piece | Approx. % | Role for the trader |
|---|---|---|
| Foreseeable fundamentals | ~75% | The undercurrent |
| "X" cyclicality | ~23% | The timing ground |
| Random | ~2% | Noise to ignore |
| Unforeseeable shocks | rare | Absorbed by protections |
Links
- Hurst operating philosophy — Ch. 1, why timing matters
- Five principles of the cyclic model — elements VI–X
- Cyclic motivation X — what we (do not) know about the cause
- Curvilinear envelope — Chapter 2's observational analysis
- Why prices change — the empirical demonstration (Ch. 9)
- Hurst tradition — chapter index