Oct 13 close Sign in

Calendar · daily rule · Energy & power

Halloween Indicator on Enerflex

What the play says

Out since Apr 30, 2026at C$36.36EFX since then +7.6%

Next move

Stays out until the close on Oct 30, 2026, when the calendar says it buys. No price can change that.

Oct 30
17 days from the Oct 13 close

Next change: the Oct 30, 2026 close

See every reason, for and against, in the Theory tester

EFX with the play, last two years

EFXPlay inPlay out

Shading shows the play's call from the close that triggered it.

Growth of C$10,000 since 2011

Halloween IndicatorBuy & hold

Log scale. After trading costs, with T-bill interest while out.

The record

The play against buying and holding EFX over exactly the same dates, after costs.

Play, since 2011Hold, since 2011Play, 5 yrsHold, 5 yrs
Annual return+14.2%+9.6%+27.0%+33.2%
Total return+659%+307%+228%+316%
Worst drawdown−62.7%−76.3%−40.9%−53.3%
Volatility29.1%41.0%32.3%46.5%
Sharpe ratio0.550.390.780.77
Time invested48%100%
Switches per year2.00

Every call, graded

Right on 19 of 30 closed calls (63%). In calls averaged +19.0%; out calls saw EFX move +0.6% on average.

CalledCallPriceUntilEFX movedResult
Apr 30, 2026OUTC$36.36now+7.6%open
Oct 31, 2025INC$17.54Apr 30, 2026+107.3%✓ right
Apr 30, 2025OUTC$8.90Oct 31, 2025+97.0%✕ wrong
Oct 31, 2024INC$9.02Apr 30, 2025−1.3%✕ wrong
Apr 30, 2024OUTC$7.84Oct 31, 2024+15.1%✕ wrong
Oct 31, 2023INC$5.34Apr 30, 2024+46.9%✓ right
Apr 28, 2023OUTC$7.90Oct 31, 2023−32.4%✓ right
Oct 31, 2022INC$6.73Apr 28, 2023+17.4%✓ right
Apr 29, 2022OUTC$8.41Oct 31, 2022−20.0%✓ right
Oct 29, 2021INC$9.95Apr 29, 2022−15.5%✕ wrong
Apr 30, 2021OUTC$7.69Oct 29, 2021+29.3%✕ wrong
Oct 30, 2020INC$4.47Apr 30, 2021+72.0%✓ right

An in call is right when the price rose before the next call; an out call is right when it fell. The latest 12 of 31 calls shown.

How the play works

  1. In at the close on the last trading day of October.
  2. Out at the close on the last trading day of April.

The research used market indexes. Applying it to one stock assumes the season carries over.

The case against

Valeriy Zakamulin tested moving-average timing on up to 155 years of U.S. stock data and found no statistically significant edge in the second half of that record. The rules earned their keep in a few severe bear markets and lagged buy and hold for long stretches in between.

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