Mean reversion · daily rule · Metals & mining
Bollinger Reversion on Perpetua Resources
What the play says
PPTA with the play, last two years
Shading shows the play's call from the close that triggered it.
Growth of C$10,000 since 2011
Log scale. After trading costs, with T-bill interest while out.
The record
The play against buying and holding PPTA over exactly the same dates, after costs.
| Play, since 2011 | Hold, since 2011 | Play, 5 yrs | Hold, 5 yrs | |
|---|---|---|---|---|
| Annual return | +7.6% | −2.3% | +27.6% | +31.5% |
| Total return | +201% | −29% | +236% | +291% |
| Worst drawdown | −78.9% | −95.2% | −45.0% | −67.7% |
| Volatility | 38.5% | 69.8% | 35.5% | 72.0% |
| Sharpe ratio | 0.34 | 0.29 | 0.75 | 0.68 |
| Time invested | 30% | 100% | ||
| Switches per year | 9.3 | 0 |
Every call, graded
Right on 97 of 141 closed calls (69%). In calls averaged +2.4%; out calls saw PPTA move +1.4% on average.
| Called | Call | Price | Until | PPTA moved | Result |
|---|---|---|---|---|---|
| Oct 2, 2026 | IN | C$29.05 | now | −14.9% | open |
| Sep 22, 2026 | OUT | C$34.85 | Oct 2, 2026 | −16.6% | ✓ right |
| Sep 14, 2026 | IN | C$31.35 | Sep 22, 2026 | +11.2% | ✓ right |
| Jun 15, 2026 | OUT | C$36.43 | Sep 14, 2026 | −13.9% | ✓ right |
| May 19, 2026 | IN | C$33.90 | Jun 15, 2026 | +7.5% | ✓ right |
| May 6, 2026 | OUT | C$40.82 | May 19, 2026 | −17.0% | ✓ right |
| Apr 29, 2026 | IN | C$35.94 | May 6, 2026 | +13.6% | ✓ right |
| Apr 1, 2026 | OUT | C$41.02 | Apr 29, 2026 | −12.4% | ✓ right |
| Mar 19, 2026 | IN | C$36.58 | Apr 1, 2026 | +12.1% | ✓ right |
| Feb 19, 2026 | OUT | C$41.33 | Mar 19, 2026 | −11.5% | ✓ right |
| Jan 30, 2026 | IN | C$36.19 | Feb 19, 2026 | +14.2% | ✓ right |
| May 26, 2025 | OUT | C$19.42 | Jan 30, 2026 | +86.4% | ✕ 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 142 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.