Mean reversion · daily rule · Consumer & retail
Bollinger Reversion on Aritzia
What the play says
ATZ with the play, last two years
Shading shows the play's call from the close that triggered it.
Growth of C$10,000 since 2016
Log scale. After trading costs, with T-bill interest while out.
The record
The play against buying and holding ATZ over exactly the same dates, after costs.
| Play, since 2016 | Hold, since 2016 | Play, 5 yrs | Hold, 5 yrs | |
|---|---|---|---|---|
| Annual return | −0.7% | +23.7% | +1.1% | +29.4% |
| Total return | −7% | +720% | +5% | +261% |
| Worst drawdown | −59.4% | −64.8% | −56.1% | −64.8% |
| Volatility | 27.0% | 43.4% | 29.1% | 48.2% |
| Sharpe ratio | 0.02 | 0.65 | 0.05 | 0.70 |
| Time invested | 24% | 100% | ||
| Switches per year | 8.1 | 0 |
Every call, graded
Right on 53 of 80 closed calls (66%). In calls averaged +0.4%; out calls saw ATZ move +7.5% on average.
| Called | Call | Price | Until | ATZ moved | Result |
|---|---|---|---|---|---|
| Oct 2, 2026 | OUT | C$122.66 | now | +19.4% | open |
| Aug 20, 2026 | IN | C$130.47 | Oct 2, 2026 | −6.0% | ✕ wrong |
| Aug 5, 2026 | OUT | C$144.73 | Aug 20, 2026 | −9.9% | ✓ right |
| Jul 23, 2026 | IN | C$132.88 | Aug 5, 2026 | +8.9% | ✓ right |
| May 25, 2026 | OUT | C$145.37 | Jul 23, 2026 | −8.6% | ✓ right |
| May 19, 2026 | IN | C$134.25 | May 25, 2026 | +8.3% | ✓ right |
| Feb 13, 2026 | OUT | C$118.63 | May 19, 2026 | +13.2% | ✕ wrong |
| Jan 28, 2026 | IN | C$107.94 | Feb 13, 2026 | +9.9% | ✓ right |
| Oct 10, 2025 | OUT | C$86.00 | Jan 28, 2026 | +25.5% | ✕ wrong |
| Oct 1, 2025 | IN | C$81.51 | Oct 10, 2025 | +5.5% | ✓ right |
| Aug 12, 2025 | OUT | C$74.57 | Oct 1, 2025 | +9.3% | ✕ wrong |
| Aug 11, 2025 | IN | C$70.95 | Aug 12, 2025 | +5.1% | ✓ 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 81 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.