Mean reversion · daily rule · Software & devices
Bollinger Reversion on Docebo
What the play says
DCBO with the play, last two years
Shading shows the play's call from the close that triggered it.
Growth of C$10,000 since 2019
Log scale. After trading costs, with T-bill interest while out.
The record
The play against buying and holding DCBO over exactly the same dates, after costs.
| Play, since 2019 | Hold, since 2019 | Play, 5 yrs | Hold, 5 yrs | |
|---|---|---|---|---|
| Annual return | +4.7% | +14.6% | +8.5% | −16.2% |
| Total return | +37% | +156% | +50% | −59% |
| Worst drawdown | −43.6% | −82.6% | −43.6% | −80.0% |
| Volatility | 29.4% | 53.4% | 29.6% | 50.8% |
| Sharpe ratio | 0.21 | 0.47 | 0.30 | −0.17 |
| Time invested | 26% | 100% | ||
| Switches per year | 9.8 | 0 |
Every call, graded
Right on 44 of 68 closed calls (65%). In calls averaged +1.1%; out calls saw DCBO move +5.2% on average.
| Called | Call | Price | Until | DCBO moved | Result |
|---|---|---|---|---|---|
| Apr 20, 2026 | OUT | C$23.62 | now | +64.8% | open |
| Apr 10, 2026 | IN | C$20.36 | Apr 20, 2026 | +16.0% | ✓ right |
| Mar 3, 2026 | OUT | C$25.09 | Apr 10, 2026 | −18.9% | ✓ right |
| Feb 18, 2026 | IN | C$22.18 | Mar 3, 2026 | +13.1% | ✓ right |
| Feb 10, 2026 | OUT | C$26.51 | Feb 18, 2026 | −16.3% | ✓ right |
| Jan 13, 2026 | IN | C$29.07 | Feb 10, 2026 | −8.8% | ✕ wrong |
| Dec 9, 2025 | OUT | C$29.98 | Jan 13, 2026 | −3.0% | ✓ right |
| Oct 29, 2025 | IN | C$35.77 | Dec 9, 2025 | −16.2% | ✕ wrong |
| Oct 23, 2025 | OUT | C$38.98 | Oct 29, 2025 | −8.2% | ✓ right |
| Sep 24, 2025 | IN | C$40.40 | Oct 23, 2025 | −3.5% | ✕ wrong |
| Jun 24, 2025 | OUT | C$37.67 | Sep 24, 2025 | +7.2% | ✕ wrong |
| Jun 13, 2025 | IN | C$35.61 | Jun 24, 2025 | +5.8% | ✓ 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 69 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.