SPX Gamma Ladder: Dealer Gamma by Strike
Each row is one SPX strike near spot, highest at the top. The bar shows how much dealer gamma sits at that strike, to scale, and the row colour shows its sign and size. The Flip Line, the call wall and the put wall are marked where they fall. A map of modeled hedging, not a forecast and not advice.
SPX DEALER GAMMA BY STRIKE
Red is negative dealer gamma, blue is positive. Colour is on a square-root scale of size, bar length is linear. Neutral with a printed 0 means the strike was priced and its net gamma is under $1M or under 0.5% of the largest strike shown. A blank row with a dashed outline is a strike inside the window, on its usual strike spacing, with nothing published.
Above 7,725, outside the published window: Swing Line 7,747.20, Call wall 7,900
Bars: the 25 strikes nearest spot, every expiration summed, dealer gamma in dollars per 1% move from the gamma the delayed option chain publishes with each contract, open interest settled Oct 21, chain as of Oct 22, 16:14 ET. This is the /gex-heatmap book.
Levels: Flip Line, Swing Line and both walls are the /gex levels book, computed Oct 22, 08:15 ET from Oct 21 settlement open interest at spot 7,757.17 (the ladder's spot is 7,663.43). That is a separate calculation from the bars, so a level need not sit where the bars change sign.
Dealer positioning is an assumption, not an observable: open interest shows that a contract exists, never which side a dealer holds.
Data table
| Strike | Dealer gamma |
|---|---|
| 7,725 | -1.6B |
| 7,720 | -550M |
| 7,715 | -263M |
| 7,710 | -579M |
| 7,705 | -369M |
| 7,700 | -5.6B |
| 7,695 | -439M |
| 7,690 | -600M |
| 7,685 | -559M |
| 7,680 | -755M |
| 7,675 | -1.5B |
| 7,670 | -791M |
| 7,665 | -938M |
| 7,660 | -625M |
| 7,655 | -505M |
| 7,650 | -8.5B |
| 7,645 | -712M |
| 7,640 | -951M |
| 7,635 | -612M |
| 7,630 | -1.2B |
| 7,625 | -1.7B |
| 7,620 | -870M |
| 7,615 | -407M |
| 7,610 | -673M |
| 7,605 | -424M |
How to read it
Bar length is linear in dollars of dealer gamma per 1% move, so a bar twice as long is twice the gamma. Colour is on a square-root scale of size, which keeps the mid-sized strikes distinguishable when one or two strikes dominate the window. Red is negative dealer gamma: under the assumed dealer positioning, hedging would tend to add to a move. Blue is positive: under the same assumption, hedging would tend to lean against one. The strip at the top is the same window in one row, lowest strike on the left.
The per-strike figures and the totals behind them are explained on the SPX GEX page, which publishes the levels marked here. The gamma exposure heatmap splits the same strikes by expiration, and the GEX calculator covers single stocks and ETFs. A markdown copy of this page carries the same table.
COMMON QUESTIONS
- What does the gamma ladder show?
- Estimated dealer gamma at each SPX strike near spot, every expiration summed, in dollars per 1% move. Bar length is to scale. Colour shows sign and size: red is negative, blue is positive, and the colour gets brighter as the gamma gets larger.
- Why is a row blank instead of zero?
- A blank row means nothing was published for that strike. A dark neutral row with a printed 0 means the strike was priced and its net gamma is under $1M or under 0.5% of the largest strike shown. The two are kept apart so a missing reading never looks like a measured zero.
- Where do the Flip Line and the walls come from?
- From the SPX levels book published on /gex, built from daily-settled open interest. The bars come from the /gex-heatmap grid, a separate calculation, so a level does not have to sit where the bars change sign.