Oct 14 close Sign in

Volume & money flow · daily rule · Healthcare

Money Flow Index on Intuitive Surgical

What the play says

Out since Aug 27, 2024at $482.35ISRG since then −12.5%

Latest reading: MFI 67.40

Next move

No single daily close can flip this call, not even one as low as $105.52 or as high as $1,688.24. It needs the MFI to cross 20 or 80, which takes more than one day from here.

Next check: the Oct 14, 2026 close

See every reason, for and against, in the Theory tester

ISRG with the play, last two years

ISRGPlay inPlay out

Shading shows the play's call from the close that triggered it.

Money Flow Index (14)

MFI

Dashed lines at 20, 80.

Growth of $10,000 since 2005

Money Flow IndexBuy & hold

Log scale. After trading costs, with T-bill interest while out.

The record

The play against buying and holding ISRG over exactly the same dates, after costs.

Play, since 2005Hold, since 2005Play, 5 yrsHold, 5 yrs
Annual return+15.8%+23.6%+20.2%+5.3%
Total return+2,311%+9,968%+149%+29%
Worst drawdown−62.8%−75.9%−24.5%−49.9%
Volatility24.7%39.8%19.5%34.6%
Sharpe ratio0.640.680.840.21
Time invested35%100%
Switches per year2.00

Every call, graded

Right on 32 of 44 closed calls (73%). In calls averaged +16.2%; out calls saw ISRG move +16.5% on average.

CalledCallPriceUntilISRG movedResult
Aug 27, 2024OUT$482.35now−12.5%open
Apr 19, 2024IN$366.34Aug 27, 2024+31.7%✓ right
Nov 30, 2023OUT$310.84Apr 19, 2024+17.9%✕ wrong
Aug 9, 2023IN$304.10Nov 30, 2023+2.2%✓ right
Apr 27, 2023OUT$295.92Aug 9, 2023+2.8%✕ wrong
Feb 27, 2023IN$231.74Apr 27, 2023+27.7%✓ right
Nov 8, 2022OUT$240.70Feb 27, 2023−3.7%✓ right
May 11, 2022IN$210.87Nov 8, 2022+14.1%✓ right
Apr 5, 2022OUT$295.92May 11, 2022−28.7%✓ right
Jan 26, 2022IN$264.46Apr 5, 2022+11.9%✓ right
Jun 30, 2021OUT$306.55Jan 26, 2022−13.7%✓ right
May 13, 2021IN$273.53Jun 30, 2021+12.1%✓ 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 45 calls shown.

How the play works

  1. In when the 14-day MFI crosses up through 20.
  2. 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.

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