Gamma Flip Explained: What the Zero Gamma Level Means

Everyone online seems to know where "the gamma flip" is. Here is what that line actually measures, why sites disagree, and why it is a model estimate, not a map of anyone's trades.

A chart circulates on X with a dashed line labeled "gamma flip." The replies are confident: below that line, dealers are short gamma, buckle up. Open two other sites for the same day and the line sits at two different prices. By the end of this piece, it should be clear what the line measures, why the numbers disagree, and why it is a modeled estimate built from open interest and assumptions — not a trigger, and not a map of anyone's trades.

What is a gamma flip?

A gamma flip, also called the zero gamma level, is the price at which a model's total net gamma exposure (GEX) would cross from positive to negative. Above-zero GEX is associated with calmer, mean-reverting moves under the model; below-zero with larger swings. It is an estimate built from open interest and assumptions, not an observed level.

Gamma exposure sums how much modeled gamma sits in the open options on a stock. The sign of that total is what people mean by "regime." The gamma flip is the modeled price where that total would pass through zero.

Illustrative example, not market data. Stock A trades at $100. Across a fuller options chain, the model shows net GEX of +$2.75M per 1% move at today's price. Somewhere below $100, the same open contracts would produce a negative total. That crossing price is the gamma flip.

How is the gamma flip level found?

Picture moving the stock price up and down while keeping the same open options, then asking the model "what would net GEX be here?" The price where that answer passes through zero is the gamma flip. It is a hypothetical: it describes the model at one point in time, not where trading will change.

Illustrative example, not market data. For Stock A:

The total crosses zero between $98 and $97. The gamma flip sits at about $97.55, roughly 2.5% below the current price. In a 7-day window the flip moves to $99.40 (0.6% below) — close enough for a "near flip" list. Different windows, different flips.

Why the gamma flip is not where the bars change color

The by-strike chart shows each strike's own modeled gamma. The flip is about the total across all strikes, at a hypothetical price. A stock can show many negative bars below its price and still have a positive total, with the flip somewhere in the middle of them.

Illustrative example, not market data. On Stock A's by-strike chart, the 97 and 96 strikes can show negative bars while the all-expiry flip still sits at $97.55. The bars reflect gamma at today's $100 price; the flip is a property of the total under a different hypothetical price.

What does it mean when price is above or below the gamma flip?

Under the model, prices on the positive side of the flip are associated with hedging that leans against moves, and the negative side with hedging that leans into them. That is a tendency under assumptions, not a rule. Which side of the flip you are on does not, by itself, tell you the regime — always check the regime label ("More stabilizing under the model" / "More volatility-amplifying under the model"). A stock can sit below its nearest flip and still show a positive regime when the model has more than one zero-crossing. It does not tell you direction, timing, or how far a stock will move, and other forces often dominate.

PredixLab's Gamma Map shows both: the flip (with distance from the current price) and the regime label for today's price. The regime is the sign of net GEX at today's price; the flip is the nearest modeled crossing. When they disagree, trust the regime label. The side of the flip is not a forecast, not support or resistance, and not a point where anyone "must" hedge a certain way.

Do dealers really flip at this level?

Nobody outside knows. Public data shows how many contracts are open, not who holds them. PredixLab counts calls as positive gamma and puts as negative, a common convention. Covered calls, spreads and institutions on both sides break that assumption, so the flip is a property of the model, not of anyone's actual book.

The convention keeps days and stocks comparable. It is not a claim about market-maker inventory — covered calls, spreads and hedged books can all sit in the same tape and pull the modeled total differently.

Why do different sites show different gamma flips?

Because each one makes different choices: which expirations count, how calls and puts are signed, which prices and Greeks are used, and when the snapshot was taken. On the same stock and day, an all-expirations flip and a 7-day flip can be far apart. Always compare like with like.

Illustrative example, not market data. Stock A's all-expiry flip is about $97.55; its 7-day flip is $99.40. Same stock, same day — different windows. Short-dated options generally carry more gamma near the money, so short windows react more. Sites that disagree on the window, sign convention or snapshot time will disagree on the number even when both are internally consistent.

How the gamma flip moves from day to day

Open interest changes after every session, and the stock price and time to expiry change too, so the flip moves. Comparing today's flip with the previous session's shows whether the modeled cushion between price and the flip widened or narrowed. A move in the flip is a change in the model's inputs, not a signal.

Illustrative example, not market data. The next session, put open interest at Stock A's 97 strike jumps. Net GEX at $100 falls from +$2.75M to +$1.2M per 1% move, and the all-expiry flip rises to $98.80 (1.2% below). The previous flip ($97.55) is shown next to the new one.

The Gamma Map splits that change into open-interest change, price and Greeks, new contracts and removed contracts, and lists the top contracts that drove it — with an unusual options activity flag when one stands out. See how PredixLab builds its options data.

Seeing the gamma flip for S&P 500 and Nasdaq-100 stocks

PredixLab's Gamma Map shows a modeled gamma flip, its distance from the current price, net GEX, the regime and call and put walls for S&P 500 and Nasdaq-100 stocks, by expiry window. It updates once per trading day. Free shows it with a 10-calendar-day delay; Premium ($20/month or $192/year) shows the latest published trading day.

Most gamma-flip charts online are for the S&P 500 index; PredixLab's Gamma Map covers individual stocks in the S&P 500 and Nasdaq-100, not the index. The coverage choice — why S&P 500 and Nasdaq-100 — is deliberate and separate from how the flip itself is defined.

The options job runs once per trading day, around 7:30 am ET (6:30 am ET in winter) the morning after the session, and can take up to an hour. Always check the data date. Each expiry window (all, 7-day, 30-day) has its own flip and walls. A "near flip" list highlights names close to the flip for the selected window.

Open the Gamma Map, or pull the same fields via MCP get_gamma_exposure (MCP docs, PredixLab MCP overview). The MCP follows the same Free and Premium delay. Free vs Premium lists what each plan includes.

What the gamma flip can't tell you

The gamma flip cannot tell you who holds the options, whether anyone is hedged, what happens intraday (the map is daily, from end-of-day open interest), which way the stock will move, when a move starts, or how far it goes. It is a modeled crossing point at one snapshot, not a trading signal and not investment advice. See PredixLab's known limitations.

Common questions

What is a gamma flip? It is the modeled price at which total net gamma exposure would cross zero, also called the zero gamma level. It is an estimate from open interest and assumptions, not an observed level.

What is the zero gamma level? It is another name for the gamma flip: the price where a model's net gamma exposure would equal zero.

How is the gamma flip calculated? Conceptually, a model asks what net gamma exposure would be at different hypothetical prices, using the same open options, and finds where the total crosses zero. Results depend on the model's choices, such as which expirations are included.

What happens below the gamma flip? Under the model, negative net gamma is associated with hedging that leans into moves and with larger swings. That is a tendency under assumptions, not a forecast of direction or size. Being below the flip alone does not mean the regime is negative — always check the regime label on the map; the nearest flip and the sign at the current price can disagree when the model has more than one zero-crossing.

Is the gamma flip support or resistance? No. It is a modeled crossing point, not a price where buying or selling is guaranteed.

Why is the gamma flip different on different websites? Expiry windows, sign conventions, inputs and snapshot times differ. An all-expirations flip and a 7-day flip for the same stock and day can be far apart.

Does PredixLab show the gamma flip? Yes, for S&P 500 and Nasdaq-100 stocks, per expiry window, with its distance from the current price and the previous session's value. It updates once per trading day. Free has a 10-calendar-day delay; Premium ($20/month or $192/year) shows the latest published trading day.

Closing

Illustrative example, not market data. Stock A in miniature: at $100, net GEX is +$2.75M per 1% move; the all-expiry flip sits near $97.55; a 7-day window puts it near $99.40; the next session lifts the flip to $98.80. Same convention, same caveats — a property of the model, not a map of anyone's book.

Open the Gamma Map · Free vs Premium

For information and independent analysis only — not investment advice. The gamma flip is a model estimate from public open interest and assumptions, not actual dealer positions. Data is daily and can be delayed or wrong; past patterns don't predict future results.