Volume & money flow · daily rule · Media & telecom
Money Flow Index on T-Mobile US
TMUS 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 2007
Log scale. After trading costs, with T-bill interest while out.
The record
The play against buying and holding TMUS over exactly the same dates, after costs.
| Play, since 2007 | Hold, since 2007 | Play, 5 yrs | Hold, 5 yrs | |
|---|---|---|---|---|
| Annual return | +6.0% | +6.1% | +11.8% | +6.8% |
| Total return | +208% | +216% | +75% | +39% |
| Worst drawdown | −53.2% | −86.3% | −17.2% | −44.0% |
| Volatility | 24.4% | 39.9% | 13.7% | 26.1% |
| Sharpe ratio | 0.30 | 0.31 | 0.61 | 0.24 |
| Time invested | 28% | 100% | ||
| Switches per year | 1.7 | 0 |
Every call, graded
Right on 20 of 32 closed calls (62%). In calls averaged +7.4%; out calls saw TMUS move +13.4% on average.
| Called | Call | Price | Until | TMUS moved | Result |
|---|---|---|---|---|---|
| Feb 20, 2026 | OUT | $212.05 | now | −27.5% | open |
| Jan 22, 2026 | IN | $182.45 | Feb 20, 2026 | +16.2% | ✓ right |
| Feb 18, 2025 | OUT | $255.06 | Jan 22, 2026 | −28.5% | ✓ right |
| Dec 20, 2024 | IN | $213.49 | Feb 18, 2025 | +19.5% | ✓ right |
| Nov 14, 2023 | OUT | $139.78 | Dec 20, 2024 | +52.7% | ✕ wrong |
| Dec 14, 2022 | IN | $135.36 | Nov 14, 2023 | +3.3% | ✓ right |
| Feb 11, 2022 | OUT | $118.36 | Dec 14, 2022 | +14.4% | ✕ wrong |
| Sep 23, 2021 | IN | $124.50 | Feb 11, 2022 | −4.9% | ✕ wrong |
| Apr 19, 2021 | OUT | $125.50 | Sep 23, 2021 | −0.8% | ✓ right |
| Mar 11, 2020 | IN | $82.20 | Apr 19, 2021 | +52.7% | ✓ right |
| Mar 1, 2019 | OUT | $68.78 | Mar 11, 2020 | +19.5% | ✕ wrong |
| Dec 26, 2018 | IN | $59.91 | Mar 1, 2019 | +14.8% | ✓ 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 33 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.