Mean reversion · daily rule · Metals & mining
Bollinger Reversion on Teck Resources
What the play says
TECK.B with the play, last two years
Shading shows the play's call from the close that triggered it.
Growth of C$10,000 since 2005
Log scale. After trading costs, with T-bill interest while out.
The record
The play against buying and holding TECK.B over exactly the same dates, after costs.
| Play, since 2005 | Hold, since 2005 | Play, 5 yrs | Hold, 5 yrs | |
|---|---|---|---|---|
| Annual return | −2.7% | +9.9% | +16.9% | +24.1% |
| Total return | −45% | +681% | +118% | +192% |
| Worst drawdown | −92.6% | −93.4% | −31.6% | −42.5% |
| Volatility | 32.4% | 53.5% | 21.2% | 43.0% |
| Sharpe ratio | 0.03 | 0.41 | 0.66 | 0.63 |
| Time invested | 23% | 100% | ||
| Switches per year | 8.4 | 0 |
Every call, graded
Right on 124 of 182 closed calls (68%). In calls averaged +0.9%; out calls saw TECK.B move +11.0% on average.
| Called | Call | Price | Until | TECK.B moved | Result |
|---|---|---|---|---|---|
| Jul 23, 2026 | OUT | C$84.07 | now | +13.6% | open |
| Jul 17, 2026 | IN | C$77.11 | Jul 23, 2026 | +9.0% | ✓ right |
| Mar 31, 2026 | OUT | C$71.90 | Jul 17, 2026 | +7.2% | ✕ wrong |
| Mar 6, 2026 | IN | C$68.34 | Mar 31, 2026 | +5.2% | ✓ right |
| Nov 25, 2025 | OUT | C$59.21 | Mar 6, 2026 | +15.4% | ✕ wrong |
| Nov 17, 2025 | IN | C$56.36 | Nov 25, 2025 | +5.1% | ✓ right |
| Aug 22, 2025 | OUT | C$46.08 | Nov 17, 2025 | +22.3% | ✕ wrong |
| Jul 24, 2025 | IN | C$47.52 | Aug 22, 2025 | −3.0% | ✕ wrong |
| Apr 23, 2025 | OUT | C$47.83 | Jul 24, 2025 | −0.7% | ✓ right |
| Mar 31, 2025 | IN | C$51.84 | Apr 23, 2025 | −7.7% | ✕ wrong |
| Mar 14, 2025 | OUT | C$59.81 | Mar 31, 2025 | −13.3% | ✓ right |
| Mar 4, 2025 | IN | C$55.16 | Mar 14, 2025 | +8.4% | ✓ 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 183 calls shown.
How the play works
- In on a close below the lower band (20-day average − 2 standard deviations).
- Out on a close above the 20-day average.
This runs against Bollinger's advice that tags of the bands are not signals. It is shown because so many traders use it.
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.