The Field Manual

How to read a gamma heatmap.

The map shows where dealers are positioned — and dealers hedge mechanically, which means their positioning pushes and pulls on price in ways you can read in advance. This page is the foundation: what every element means, how a structure reads (with a worked example), and the discipline that keeps a correct read from becoming a bad trade. The full structure playbook — all nine named shapes and the comparison reads — lives in the members' Field Guide.

Start here

The whole language is four things.

Learn these four and every screen on FlowMonkey speaks the same words. Nothing on the site uses a term this section doesn't teach.

1 · The walls
The floor is the heaviest put level below price — the shelf dealer hedging defends first. The cap is the heaviest call level above — the ceiling hedging leans against. Together they frame the day, and every read on the site names them.
2 · The ★ Apex
The single heaviest level on the whole board — more dealer exposure than any other strike. Graded across five years: it is sticky when price is on it, and it is not a magnet — we measured that, and say so.
3 · The flip
The price where the book changes character. Above it, hedging absorbs moves and the tape tends to stick. Below it, hedging amplifies and the same market travels faster. A character line, not a destination.
4 · The Verdict
Every board's read, written out: what's happening, the shape of the day, how far days like this travel, what to watch for — and always, where the read is wrong. If you only read one thing on a board, read this.

That's the language. Everything below is depth — how the four behave, how to read them together, and the discipline that keeps a correct read from becoming a bad trade.

Part 1

What the map actually is

When someone buys an option, a market maker usually takes the other side — and market makers do not gamble. They hedge by buying and selling the stock itself, constantly, mechanically, to stay neutral. Gamma measures how hard they have to re-hedge as price moves. The map adds that up at every strike and paints it: one row per strike, one column per expiry, the color and size showing how much dealer hedging lives there.

That single number per strike carries a behavior. Where dealers are long gamma (green), their hedging pushes AGAINST price moves — rallies get sold into, dips get bought. Price slows down, sticks, pins. Where dealers are short gamma (pink), their hedging pushes WITH the move — the further price goes, the more they must chase it. Moves stretch and accelerate.

Green · positive gamma
Dealers dampen. Mean reversion, pinning, ranges that stick. A big green level is where a move goes to die — which makes it a destination, and a place moves stall.
Pink · negative gamma
Dealers amplify. Momentum, stretched moves, air underneath. A big pink level is not support — hedging there pushes price further, not less.

The one-sentence version: green absorbs, pink accelerates, and the biggest number on the board — the ★ Apex — is the strike the whole session bends around.

Part 2

The five things on the map

★ The Apex
The strike carrying the largest total gamma, sign ignored — the size of the pile is what pulls, not its direction. Its sign then tells you HOW it behaves when price arrives: positive Apex = pin and chop; negative Apex = a level price can slingshot around. The Apex is measured per expiry scope — the 0DTE Apex and the weekly Apex are different questions with different answers.
The cap (largest positive level above price)
Where rallies meet supply: as price rises toward it, dealers sell to stay hedged — supply arrives exactly where the move is trying to extend. This is where longs get PAID, not where longs get placed.
The floor (largest level below price)
If it is green, dealers lean against dips there — a real floor. If it is pink, nothing obliges a dealer to catch price there — that is not a floor, it is a label on thin air.
The flip
The price where the book changes sign — cross it and the market's character changes from sticky to slippery (or back). A session trading near its flip can change personality mid-day.
Thin zones
Stretches where exposure is near zero on both sides. No pull, no damping, nothing obliging a dealer to act — price has no structural reason to slow down through them. Space plus a fresh move equals fast travel.

The map prices every level by how likely YOUR ticker is to actually reach it today — measured on that symbol's own range, decaying as the session burns down. “In play today” and “almost out of reach” are measurements, not moods.

Part 3

The structures

Individual levels matter less than the SHAPE they make together. Nine shapes cover most sessions, and each carries its own behavior. You do not have to spot them yourself: the map reads the book live, names the structure in play as a colored label on The Read, and prints what to watch for under it. Here is one of the nine, so you can see how a structure reads:

Springboard — solid floor below, amplifying air above
PRICE
★floor
Dips get absorbed at the floor; a push higher gets chased by dealer hedging instead of sold into. Both forces point up — the shape that carries conviction.
The other eight shapes — and the comparison reads

The full playbook — the mirror of the Springboard, the pin shapes, the migration signal, the warning shape, and the three comparison reads that separate real structure from one trade wearing a structure costume — lives in the members' Field Guide, next to the live maps that name them. Every member card also prints the what-to-watch line for the structure in play, so the knowledge is at the point of use, not in a PDF.

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The map names the structure in play so you are never guessing which shape you are looking at — the label, its color, and what to watch print live on The Read.

Part 4

Read one expiry at a time

Adjacent expiries routinely disagree — the same strike can be strongly positive on one date and strongly negative on the next. Read them blended together and you can end up with structure that exists on NEITHER: an averaged level pointing at a strike that no actual expiry supports.

So the rule is mechanical: pick the expiry you are trading first, then read only that column. Day-trading 0DTE? The front expiry IS your map — gamma per contract peaks at expiry, hedging flow is heaviest there, and the structure decays fastest. That is why Compass defaults to the front expiry and why the map's 0DTE / Week / All views each compute their OWN Apex and walls instead of sharing a blend.

Averaging expiries is the error the map punishes. Pick your date, read its column, and let The Read's live survival checks (taught in the Field Guide) judge whether a level outlives the roll.

Part 5

The daily workflow

Before the open — frame the day
Read the front expiry: where is the Apex relative to price? Where are the cap and floor, and is either side missing? Note the flip. Check the levels' reach odds — a level “almost out of reach” is context, not a target.
The first 15–30 minutes — let it settle
The opening auction reshuffles the book while positions roll in. Early levels move; early reads age fast. The patient version of every setup exists again at 10:00 with a settled book behind it.
Targets are not entries
The big level is where price is GOING — enter there and you are buying after the move you wanted is spent. Negative levels on the way down are WAIT (no floor — hedging pushes price further, not less). The first big positive level back toward price is where dealers absorb and risk becomes definable — that is where you stand. Mistaking a destination for an entry is how a correct read becomes a bad trade.
Through the session — watch the deltas
The Read updates as the book moves. Growth at a level ahead of price is the destination strengthening; the Apex migrating is the day re-deciding; the frame widening or flipping sign changes the regime mid-session. The Read's comparison checks are live, not a morning-only exercise.
Exits — the measured gap
Our own graded record says the exit, not the entry, is where results leak: cards routinely tag a strong peak and give most of it back. When a plan target is hit, the plan says take it — that is what the target was for. And winners here typically dip hard before running; sizing so the normal dip does not shake you out IS the strategy.
The seal

Written down before the open

Every morning, the levels are sealed
At 9:12 ET — eighteen minutes before the bell — the day's levels for every core board (Apex, walls, gamma flip, expected move) are written into one file and fingerprinted with SHA-256. Each day's file also contains the previous day's fingerprint, so silently editing any past session would break every hash after it. Levels published after the close prove nothing; ours are on the record before the market can make them right or wrong.
Check it yourself
The hash index is public at /api/public/ledger and each session's exact sealed bytes at /api/public/ledger/{date}. Download a file, run sha256sum on it, and you get the same fingerprint the index shows. A historical archive back to 2021 is published alongside it, honestly labeled: boards written at the time say recorded, boards computed later from historical chains say reconstructed — and neither is called a seal, because only the chain that starts before the bell can be one.
Part 6

The mistakes that cost money

Treating every drawn level as equal
Most levels on a chart will never be touched today. Distance is everything — a wall four percent away is decoration, not resistance. Trade the levels that are actually in play.
Calling a pink level 'support'
Negative gamma below price is not a floor. Nothing there obliges anyone to buy. If the biggest thing under the market is pink, the honest description is “no floor” — plan accordingly.
Trusting a level that dies tomorrow
Front-expiry structure evaporates at the settle. Levels have a short shelf life — yesterday's wall surviving to today is common, but it is a fresh question every session, and holding a position past a roll on the strength of an expiring level is unforced error.
Reading the blend
The all-expiry view is for the survival checks, not for picking your intraday level. Part 4 is the rule; the blended Apex can point at a strike that is strong on no actual day.
Ignoring the disagreement
When the index maps disagree with each other — one bullish shape, one bearish, one pinned — the structural edges cancel and chop rules. The only edge left is fading the outer boundary of a range, and a mid-range entry has none at all. Disagreement IS a read: it says stand down.
Part 7

What we refuse to tell you

We used to quote the odds that a dealer wall would hold. Then we ran the test nobody runs: we compared real walls against random prices the same distance away — and they scored the same. So we deleted the claim instead of selling it. What survived that purge is what the product shows today: how far your symbol actually travels (the reach odds), what the book is doing right now (The Read), and a nightly grade on everything we surface — wins and misses both.

You will not find win-rate promises on this page or anywhere else on the site. The map describes dealer positioning and its mechanical behavior. It does not predict. Anyone who tells you a level “holds 80% of the time” has not run the control.

The point of the platform is not to protect a number. It is to show you what the book is actually doing — including when the book says “no edge today.” Silence is part of the edge.

Now read a live one.

The free SPY board is the real map with a 15-minute delay — no login. The structure this page teaches — the grid, the walls, the ★ Apex — is visible on it right now; the full read is members-only.

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Educational content. Not financial advice. Dealer-positioning values are estimates built from listed options data; market data may be delayed or incomplete.