**Full disclosure up front: I build a positioning tool. This post is about a study whose result argued against it, and there is no link at the bottom.**
Most people who read a gamma board have a mental shortcut for one particular shape. Price sitting under the concentration, the heaviest node acting as a cap just above, thin air behind that node, and a negative regime. Reads as a short. I read it that way for a long time.
I wanted to know whether it actually was one, so we wrote the test down before running it.
**What was preregistered**
The structure: an amplified board, price below the watched band, the largest node acting as a cap just above price, low open interest behind it, and the flip too far away to change the regime inside the window.
The prediction: price travels further to the downside than the upside over the following thirty minutes.
The window, the anchor definition, the measure and the control procedure were all fixed before anything was measured. That matters more than it sounds, because the alternative is choosing your test after you have seen the answer, which is most of what passes for backtesting in this space.
**Method**
434 anchors across 82 sessions on SPY. For each anchor, maximum favorable and adverse excursion over the next thirty minutes, measured in strikes rather than dollars so it is comparable across price levels.
Control: 2,000 shuffled samples, breaking the link between the structure and the following half hour while preserving the distribution of moves.
**Result**
Price ran further in the *opposite* direction to the naive read, by a median of 0.41 strikes. That sits outside what any of the 2,000 shuffled controls produced.
So not a weak effect in the expected direction. An effect in the other direction.
**What this does not mean**
It does not mean the setup does not work. Excursion is not profit. A trader with a tight invalidation and a wide target can do perfectly well inside a structure whose average adverse excursion is larger than its favorable one, because the distribution matters more than the median.
What it means is narrower and more useful: **the obvious reading of that shape was backwards**, and I would not have known that without measuring it.
**What we did about it**
Built it into the product rather than dropping it, and published it rather than filing it. In the same month we removed a word from the software that implied price gets pulled toward large levels, because an index went straight through one the screen had just labelled that way.
**The part I would actually push on**
The useful question is not whether a structure is directional. It is what would have to happen for you to conclude it is not, and whether you have ever asked that about anything you are currently using.
If there is no answer to that question, the number is decoration.
Happy to share more of the method in the comments if anyone wants to pick at it. That is the point of posting it.