Oct 14 close Sign in

Candles & chart patterns · daily rule · Industrials & materials

Engulfing Switch on GFL Environmental

What the play says

In since Sep 29, 2026at C$59.84GFL since then +2.3%

Latest reading: Pattern 0.00

Next move

Stays in unless a daily close lands below C$60.87.

C$60.87
−0.6% from the Oct 14 close of C$61.24

Next check: the Oct 15, 2026 close

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

GFL with the play, last two years

GFLPlay inPlay out

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

Engulfing patterns (+1 bullish, −1 bearish)

Pattern

Dashed line at 0.

Growth of C$10,000 since 2020

Engulfing SwitchBuy & hold

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

The record

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

Play, since 2020Hold, since 2020Play, 5 yrsHold, 5 yrs
Annual return+16.4%+16.6%+10.4%+4.9%
Total return+170%+174%+63%+27%
Worst drawdown−33.1%−39.3%−33.1%−39.3%
Volatility23.4%31.8%21.7%29.0%
Sharpe ratio0.640.550.390.18
Time invested45%100%
Switches per year7.50

Every call, graded

Right on 22 of 49 closed calls (45%). In calls averaged +4.4%; out calls saw GFL move +0.8% on average.

CalledCallPriceUntilGFL movedResult
Sep 29, 2026INC$59.84now+2.3%open
Aug 5, 2026OUTC$57.69Sep 29, 2026+3.7%✕ wrong
May 7, 2026INC$50.77Aug 5, 2026+13.6%✓ right
Apr 8, 2026OUTC$61.31May 7, 2026−17.2%✓ right
Mar 26, 2026INC$55.03Apr 8, 2026+11.4%✓ right
Oct 6, 2025OUTC$64.16Mar 26, 2026−14.2%✓ right
Aug 29, 2025INC$68.60Oct 6, 2025−6.5%✕ wrong
Jun 27, 2025OUTC$67.98Aug 29, 2025+0.9%✕ wrong
Jun 23, 2025INC$68.63Jun 27, 2025−1.0%✕ wrong
Apr 28, 2025OUTC$66.98Jun 23, 2025+2.5%✕ wrong
Mar 31, 2025INC$69.36Apr 28, 2025−3.4%✕ wrong
Dec 5, 2024OUTC$64.86Mar 31, 2025+6.9%✕ wrong

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 50 calls shown.

How the play works

  1. Bullish engulfing: after a decline, a down day (close below open) is followed by an up day that opens at or below the prior close and closes at or above the prior open.
  2. Bearish engulfing: after a rise, an up day is followed by a down day that opens at or above the prior close and closes at or below the prior open.
  3. In at the close of a bullish engulfing day. Out at the close of a bearish engulfing day. Otherwise the rule keeps its last call.

A decline (or rise) means the prior close is below (or above) the close 5 sessions before it. Nison and Bulkowski require a prior trend but give no number.

Nison weighs support, resistance and confirmation, which a mechanical rule cannot judge. No confirmation day is required here.

Shadows are ignored, as both Nison and Bulkowski allow. One edge of the new body may equal the old body's edge, as in the TA-Lib pattern library, but not both.

Crypto trades around the clock, so a coin's daily open is just the prior close. For coins the open is taken as the prior close, and the pattern becomes a close beyond the prior day's open.

Where the rules come from

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.

Read the skeptic's scoreboard

Free account

Know the moment the light flips on your stocks.

Follow your stocks and get an email with the analysis the evening a light flips. Member tools are free until January 1, 2027.