Volume & money flow · daily rule · Software & devices
Money Flow Index on Datadog
DDOG with the play, last two years
Shading shows the play's call from the close that triggered it.
Money Flow Index (14)
Dashed lines at 20, 80.
Growth of $10,000 since 2019
Log scale. After trading costs, with T-bill interest while out.
The record
The play against buying and holding DDOG over exactly the same dates, after costs.
| Play, since 2019 | Hold, since 2019 | Play, 5 yrs | Hold, 5 yrs | |
|---|---|---|---|---|
| Annual return | +12.6% | +34.6% | +11.7% | +12.8% |
| Total return | +128% | +694% | +74% | +82% |
| Worst drawdown | −64.2% | −68.1% | −64.2% | −68.1% |
| Volatility | 40.3% | 60.0% | 46.0% | 59.5% |
| Sharpe ratio | 0.42 | 0.74 | 0.38 | 0.43 |
| Time invested | 35% | 100% | ||
| Switches per year | 1.1 | 0 |
Every call, graded
Right on 4 of 8 closed calls (50%). In calls averaged +30.2%; out calls saw DDOG move +51.0% on average.
| Called | Call | Price | Until | DDOG moved | Result |
|---|---|---|---|---|---|
| Jun 2, 2026 | OUT | $269.13 | now | +5.3% | open |
| Jan 21, 2026 | IN | $123.46 | Jun 2, 2026 | +118.0% | ✓ right |
| Jul 8, 2025 | OUT | $145.94 | Jan 21, 2026 | −15.4% | ✓ right |
| Dec 31, 2024 | IN | $142.89 | Jul 8, 2025 | +2.1% | ✓ right |
| May 31, 2023 | OUT | $94.91 | Dec 31, 2024 | +50.6% | ✕ wrong |
| Jan 24, 2022 | IN | $136.07 | May 31, 2023 | −30.2% | ✕ wrong |
| Feb 9, 2021 | OUT | $117.85 | Jan 24, 2022 | +15.5% | ✕ wrong |
| Nov 3, 2020 | IN | $90.14 | Feb 9, 2021 | +30.7% | ✓ right |
| Oct 10, 2019 | OUT | $35.60 | Nov 3, 2020 | +153.2% | ✕ wrong |
An in call is right when the price rose before the next call; an out call is right when it fell. The latest 9 of 9 calls shown.
How the play works
- In when the 14-day MFI crosses up through 20.
- Out when it crosses down through 80.
The creators also stress divergences, which this rule ignores.
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.