Mean reversion · daily rule · Semiconductors
Bollinger Reversion on Astera Labs
What the play says
ALAB with the play, last two years
Shading shows the play's call from the close that triggered it.
Growth of $10,000 since 2024
Log scale. After trading costs, with T-bill interest while out.
The record
The play against buying and holding ALAB over exactly the same dates, after costs.
| Play, since 2024 | Hold, since 2024 | Play, 5 yrs | Hold, 5 yrs | |
|---|---|---|---|---|
| Annual return | +15.8% | +85.2% | +15.8% | +85.2% |
| Total return | +44% | +359% | +44% | +359% |
| Worst drawdown | −62.5% | −63.7% | −62.5% | −63.7% |
| Volatility | 49.4% | 93.7% | 49.4% | 93.7% |
| Sharpe ratio | 0.46 | 1.08 | 0.46 | 1.08 |
| Time invested | 28% | 100% | ||
| Switches per year | 9.7 | 0 |
Every call, graded
Right on 17 of 24 closed calls (71%). In calls averaged +4.4%; out calls saw ALAB move +24.6% on average.
| Called | Call | Price | Until | ALAB moved | Result |
|---|---|---|---|---|---|
| Sep 17, 2026 | OUT | $293.56 | now | +10.8% | open |
| Sep 14, 2026 | IN | $257.04 | Sep 17, 2026 | +14.2% | ✓ right |
| Aug 4, 2026 | OUT | $361.67 | Sep 14, 2026 | −28.9% | ✓ right |
| Jul 16, 2026 | IN | $319.74 | Aug 4, 2026 | +13.1% | ✓ right |
| Apr 7, 2026 | OUT | $118.99 | Jul 16, 2026 | +168.7% | ✕ wrong |
| Mar 30, 2026 | IN | $100.27 | Apr 7, 2026 | +18.7% | ✓ right |
| Mar 11, 2026 | OUT | $124.71 | Mar 30, 2026 | −19.6% | ✓ right |
| Feb 12, 2026 | IN | $126.58 | Mar 11, 2026 | −1.5% | ✕ wrong |
| Feb 6, 2026 | OUT | $169.85 | Feb 12, 2026 | −25.5% | ✓ right |
| Jan 30, 2026 | IN | $150.62 | Feb 6, 2026 | +12.8% | ✓ right |
| Dec 1, 2025 | OUT | $165.19 | Jan 30, 2026 | −8.8% | ✓ right |
| Nov 13, 2025 | IN | $144.47 | Dec 1, 2025 | +14.3% | ✓ 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 25 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.