The Field Manual

How to read a gamma heatmap.

The map is an estimate of where dealers must hedge — the sign of each strike is inferred from the chain — and dealers hedge mechanically, which shapes how much price moves 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 lid is the heaviest positive level above price — where hedging absorbs a rally. The shelf is the heaviest level below — not a defended floor, and if it is negative gamma there is no shelf at all. Every read on the site names them; neither is a bounce point.

2 · The ★ Apex

The single heaviest level on the whole board. Sitting still, it is not a magnet — we measured that, and say so. What matters is change: an Apex being built within 1% of price has been reached more often; one being unwound is avoided.

3 · The flip

Just the price where net gamma changes sign. What matters is the sign at price: positive gamma absorbs, negative gamma amplifies — about a quarter more movement ahead. The flip is context, not a switch that decides how every level behaves.

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. Moves get absorbed and ranges narrow. Where dealers are short gamma (pink), their hedging pushes WITH the move — the further price goes, the more they must chase it. Measured, negative gamma has run about a quarter more movement ahead. None of this says which way.

Green · positive gamma

Dealers absorb. Heavy green size sitting right at price narrows the range from both sides — a pin. That is range compression, not support, and a big green level away from price is not somewhere price is headed.

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 amplifies, and the biggest number on the board — the ★ Apex — tells you nothing about direction while it sits still. Watch it change.

Part 2

The five things on the map

★ The Apex

The strike carrying the largest total gamma, sign ignored. A still Apex does not pull price — a dominant one far from price is reached less often than a random level the same distance away. Change is what counts: an Apex being built within 1% of price has been reached more often, one being unwound is avoided, and an Apex stepping to a new strike ahead of price has come before the move continuing. The Apex is measured per expiry scope — the 0DTE Apex and the weekly Apex are different questions with different answers.

The lid (heaviest positive level above price)

As price rises toward it, dealers sell to stay hedged — positive gamma absorbs the rally. On its own a lid is no better than any level the same distance away; the edge belongs to the Lid pattern (a heavy lid with amplifying gamma beneath), the one level shape that has held up on both clocks.

The shelf (heaviest level below price)

Graded, a shelf held declines no better than a random level the same distance away — it is where positioning sits, not a defended floor. If it is pink there is no shelf at all: negative gamma amplifies, so the read says “no shelf — amplifying.”

The flip

The price where net gamma changes sign — nothing more. It tells you whether the book at price absorbs or amplifies. A flip between price and a far level makes that level harder to reach; it is not a trigger and not a bounce point.

Pockets

Stretches where exposure is near zero. The popular story says price races through them; we measured the opposite — a pocket between price and a nearby level makes that level HARDER to reach. A pocket near, or a flip far, is what the read calls a checkpoint.

The map prices every level by how likely YOUR ticker is to actually reach it today — distance against that symbol's own range, plus the path (pocket near, flip far), 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; we graded every one against a level the same distance away, and most describe how much the session moves, not which way. 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:

The Lid — heavy level above, amplifying air below

★lid

PRICE

Positive gamma above price absorbs; negative gamma below amplifies. It is the one level shape with a measured edge on both clocks: in this pattern the lid has held 84.8% of next sessions against 75.5% for any level the same distance out (70,562 boards), and the edge shows up intraday too. What usually follows is price staying underneath, not a breakdown.

The other eight shapes — and the comparison reads

The full playbook — the mirror of the Lid, the pin shapes, the Apex-stepping 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 lid and shelf, and is either side missing? Note the sign at price. Check the levels' reach words — a level “almost out of reach” is context.

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.

Levels are not entries

A big level is not where price is going, and it is not a bounce point either — graded, price turns at a node about as often as a coin flip. Negative levels on the way down are not support (no shelf — hedging pushes price further, not less). Use levels to frame how far the day can reach and where the read is wrong, never as a reason to enter on their own. Every read carries the price that invalidates it.

Through the session — watch the change

The Read updates as the book moves, and change is the only directional read. An Apex being built near price has been reached more often; one being unwound is avoided; an Apex stepping ahead of price has come before the move continuing; size growing above price faster than below has tilted the next half hour higher. The Read's 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 your plan's exit is hit, the plan says take it — that is what the exit 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. Focus on the levels that are actually in reach.

Calling a pink level 'support'

Negative gamma below price is not a shelf. Nothing there obliges anyone to buy. If the biggest thing under the market is pink, the honest description is “no shelf” — 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

The index maps are worth reading together. When all three — SPY, QQQ and IWM — are negative gamma at once, a wider day is much more likely (how far, never which way). When they disagree, we tested whether that predicts chop and it did not; it simply means the complex gives you no read, and no read is a reason to 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 words), 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.

Part 8

What we tested and threw out

Each of these is a popular teaching. We graded each one against a level the same distance away, or a matched moment, and none of them showed an edge — so none of them appears on the site.

Levels as bounce points. Once price reaches a node it turns back about as often as a coin flip.
“Fresh levels are stronger; retests weaken.” Reaction at a level rose with the number of touches for random levels too — it is chop, not decay.
Power hour at the levels. The last half hour near a level was no wilder than away from one.
“Levels are weaker in expiry week.” They held no worse than in any other week. They just move more.
“Fast change at a node means volatility.” Once the move that caused the change was accounted for, it did not.
Walls as a container. The close landed between the walls less often than inside a same-width band around the prior close.
A still Apex as a magnet. Not while it sits still — only change, building or unwinding, moved the odds.
Expiry weighting and “confirmation” across dates. Weighting a level by its expiry, or trusting it more because several dates agree, showed no edge.
0DTE and expiry-day pins to a still strike. No pull beyond a random level; the late-day version that tested is an Apex being built near price.
“Price flies through thin gamma.” A pocket in front of a nearby level made it harder to reach, not easier.

What survived is short: the sign of the book (how much, not which way), size at price narrowing the range, the Lid pattern, and change — the Apex building, unwinding or stepping ahead of price.

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.

Open the free SPY board Get full access

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