Mean reversion · daily rule · Software & devices
Bollinger Reversion on Nebius Group
What the play says
NBIS 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 NBIS over exactly the same dates, after costs.
| Play, since 2024 | Hold, since 2024 | Play, 5 yrs | Hold, 5 yrs | |
|---|---|---|---|---|
| Annual return | +58.0% | +259.8% | +58.0% | +259.8% |
| Total return | +137% | +1,017% | +137% | +1,017% |
| Worst drawdown | −18.0% | −58.3% | −18.0% | −58.3% |
| Volatility | 40.0% | 112.9% | 40.0% | 112.9% |
| Sharpe ratio | 1.24 | 1.65 | 1.24 | 1.65 |
| Time invested | 9% | 100% | ||
| Switches per year | 5.3 | 0 |
Every call, graded
Right on 7 of 10 closed calls (70%). In calls averaged +18.2%; out calls saw NBIS move +71.1% on average.
| Called | Call | Price | Until | NBIS moved | Result |
|---|---|---|---|---|---|
| Aug 3, 2026 | OUT | $212.58 | now | −2.7% | open |
| Jul 29, 2026 | IN | $148.22 | Aug 3, 2026 | +43.4% | ✓ right |
| Feb 13, 2026 | OUT | $98.01 | Jul 29, 2026 | +51.2% | ✕ wrong |
| Jan 30, 2026 | IN | $85.19 | Feb 13, 2026 | +15.0% | ✓ right |
| Dec 22, 2025 | OUT | $93.23 | Jan 30, 2026 | −8.6% | ✓ right |
| Dec 17, 2025 | IN | $75.45 | Dec 22, 2025 | +23.6% | ✓ right |
| Dec 1, 2025 | OUT | $100.15 | Dec 17, 2025 | −24.7% | ✓ right |
| Nov 12, 2025 | IN | $94.36 | Dec 1, 2025 | +6.1% | ✓ right |
| Apr 23, 2025 | OUT | $22.96 | Nov 12, 2025 | +311.0% | ✕ wrong |
| Mar 28, 2025 | IN | $22.31 | Apr 23, 2025 | +2.9% | ✓ right |
| Nov 15, 2024 | OUT | $17.60 | Mar 28, 2025 | +26.8% | ✕ wrong |
An in call is right when the price rose before the next call; an out call is right when it fell. The latest 11 of 11 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.