James Marsden Hurst 1924—2005

Chapter 3.6 Verify Your Chart Patterns

Case Perkin-Elmer (1961)

Chapter 3's case study: two triangles on Perkin-Elmer, four periodicities measured on the daily chart, and cyclic analysis predicting the 'failure' that charting suffers.

On this page

Who this entry is for — A real case, taken from a charting manual of the era: same chart, two readings. The chartist applies the triangle rule; the model lists the state of the cycles — and sees further.

Source: J. M. Hurst, The Profit Magic of Stock Transaction Timing, Prentice-Hall, 1970 — Chapter 3, How to Tell in Advance if a Chart Pattern Will "Fail" (pp. 59–61, Fig. III-9). Stock: Perkin-Elmer, daily high-low chart, March–September 1961.


Prerequisites

Triangles and cyclic analysis — the mechanism. Here: the mechanism tested on real data.


The four measured periodicities

In plain words — Before judging the triangles, Hurst measures the stock's cycles with Chapter 2's method: lows, counts, averages. He finds four, nested roughly three-to-one or two-to-one.

On the Perkin-Elmer daily, counting the lows yields a complete ladder — and a fine lesson in applied nominality, with the deviations 1961 imposes on the reference values:

Lows counted Samples Average duration Model nominal
A, B, C 2 13.9 weeks 13 weeks
points 1–7 6 4.6 weeks 3.25 weeks (1961 equivalent)
12 2.3 weeks 1.625 weeks (1961 equivalent)
1.15 weeks half the previous (not tabulated in the model)
Original Fig. III-9 — the two triangles on Perkin-Elmer
The original 1970 plate: Fig. III-9, the Perkin-Elmer daily with the charting manual's two triangles and the letter/number lows.

First triangle: the predicted "failure"

In plain words — The charting rule says: a triangle continues the trend that preceded it (here: up). But all four cycles pointed down. Downside exit: the rule fails, the model does not.

The small triangle at the top of the chart is made of three cycles of the 1.15-week periodicity, magnitude variation clearly visible — "more properly the chartist's flag". At the moment of the break, the state of the cycles:

Cycle Position Direction
13.9 weeks 8 weeks along hard down
4.6 weeks 3.8 weeks along hard down
2.3 weeks 1.3 weeks along hard down
1.15 weeks 1.1 weeks along hard down

"Is it any wonder that a downside breakout occurred?". But the point is another: the charting rule for triangles — probabilities favour the continuation of the preceding trendfailed here, and the manual the case comes from recorded it as a failure without explanation. Knowledge of the cycles allowed the failure to be forecast in advance: that is what turns the pattern from a bet into information.


Second triangle: agreeing with the chartist — knowing why

The large triangle on the right forms differently: one and most of a second cycle of the 4.6-week periodicity while the 13.9-week cycle goes over its top — the double-top mechanics. State of the cycles at formation:

Cycle Position Direction
13.9 weeks 7.4 weeks along hard down
4.6 weeks 3.6 weeks along hard down
2.3 weeks 1.3 weeks along hard down
1.15 weeks bottoming out flat to up

On top of that, the preceding 13.9-week cycle had printed a lower low: the sum of all components longer than 13.9 weeks was falling too. Prediction: downside breakout — "and again be right". Here the chartist's rule said the same; the difference is that the model knows why, and would have spoken even when the rule was silent or wrong.

Card — The case's method

  • First measure the stock's cycles (lows, counts, averages — Ch. 2).
  • Then fill in the state table: for each cycle, how far along and pointing where.
  • Finally read the pattern: the exit goes the way the dominant cycles row.