Mean reversion · daily rule · Metals & mining
Bollinger Reversion on Pan American Silver
What the play says
PAAS 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 PAAS over exactly the same dates, after costs.
| Play, since 2005 | Hold, since 2005 | Play, 5 yrs | Hold, 5 yrs | |
|---|---|---|---|---|
| Annual return | +5.7% | +7.3% | +13.2% | +17.7% |
| Total return | +234% | +361% | +85% | +125% |
| Worst drawdown | −64.3% | −79.4% | −23.6% | −54.0% |
| Volatility | 26.4% | 48.9% | 20.7% | 47.0% |
| Sharpe ratio | 0.27 | 0.35 | 0.52 | 0.50 |
| Time invested | 26% | 100% | ||
| Switches per year | 8.7 | 0 |
Every call, graded
Right on 119 of 189 closed calls (63%). In calls averaged +1.4%; out calls saw PAAS move +2.5% on average.
| Called | Call | Price | Until | PAAS moved | Result |
|---|---|---|---|---|---|
| Sep 28, 2026 | IN | C$64.86 | now | −2.3% | open |
| Jun 16, 2026 | OUT | C$72.50 | Sep 28, 2026 | −10.5% | ✓ right |
| Jun 5, 2026 | IN | C$66.01 | Jun 16, 2026 | +9.8% | ✓ right |
| May 6, 2026 | OUT | C$76.77 | Jun 5, 2026 | −14.0% | ✓ right |
| Apr 28, 2026 | IN | C$71.15 | May 6, 2026 | +7.9% | ✓ right |
| Mar 31, 2026 | OUT | C$75.60 | Apr 28, 2026 | −5.9% | ✓ right |
| Mar 18, 2026 | IN | C$70.55 | Mar 31, 2026 | +7.2% | ✓ right |
| Nov 10, 2025 | OUT | C$51.74 | Mar 18, 2026 | +36.4% | ✕ wrong |
| Oct 21, 2025 | IN | C$49.04 | Nov 10, 2025 | +5.5% | ✓ right |
| Aug 5, 2025 | OUT | C$39.47 | Oct 21, 2025 | +24.3% | ✕ wrong |
| Jul 30, 2025 | IN | C$37.25 | Aug 5, 2025 | +6.0% | ✓ right |
| Apr 11, 2025 | OUT | C$35.19 | Jul 30, 2025 | +5.8% | ✕ 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 190 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.