01 / LEARN
Gamma Exposure
Learn why buying and selling linked to options can slow a move down or help it continue.
What is Gamma Exposure?
Gamma tells you how an option’s response to a price move can change. An option is a contract linked to something such as a stock. Its value can rise or fall when that stock moves.
Start with two words: delta tells you roughly how much the option’s value responds to a small price move right now. Gamma tells you how that response changes as the stock moves.
A simple example
At one stock price, a small move might change an option’s value by about 50 cents. At a higher stock price, the same-sized move might change it by about 60 cents. The option has become more responsive. Gamma helps describe that change.
GEX means gamma exposure. It brings gamma from many options together. Your indicator uses that information to mark prices worth watching.
Why watch those prices? Firms that trade options may need to buy or sell stocks or futures as their risk changes. Those extra trades can affect price.
A little more detail: options and gamma
A call option gives its owner the right to buy at an agreed price. A put gives the right to sell. That agreed price is called the strike. The right lasts until a set date, with exercise rules depending on the contract.
Gamma measures how delta changes for a small move in the price the option follows, with other factors held steady. Standard purchased calls and puts have positive gamma; selling them reverses the sign. Options near their strike and close to ending can be especially sensitive.
Why is it important?
Gamma can help explain why one market keeps bouncing back and another keeps moving in the same direction.
A dealer is a firm that buys and sells options with other traders. To reduce the risk of those trades, it may place balancing trades in stocks or futures. That is called hedging.
Depending on the options the dealer holds, its balancing trades may work in one of two ways:
| Behavior | What the dealer does | What that could do to price |
|---|---|---|
| Against the move Long gamma | Buys as price falls. Sells as price rises. | Help slow the move down. |
| With the move Short gamma | Buys as price rises. Sells as price falls. | Help the move continue. |
“Positive” does not mean price must rise. “Negative” does not mean price must fall. These ideas describe how movement may behave, in either direction.
Your indicator estimates exposure from options data. It cannot see every dealer’s actual holdings. News and other traders can also overpower any hedging effect.
How to use Gamma Exposure
Start with the nearest marked price above the market and the nearest one below it. You do not need to watch every line at once.
Think of a line as an area to watch.
Price is not guaranteed to stop exactly on the line. It can reverse a few points before reaching it, briefly move past it, or continue through. A line at 20,100 could see a turn near 20,097 or 20,103. Those are made-up examples, not a fixed three-point rule.
- Watch as price gets close. You do not need an exact touch to notice a reaction. Getting close is not, by itself, a reason to trade.
- Watch whether price turns or keeps going. A brief move past the line is different from price moving beyond the surrounding area and staying there.
- Watch the return to the area. Coming back to test it is called a retest. Price might break above, pull back near the level, then rise again without touching the exact number.
- Decide in advance what would change your view. Use the market's recent movement and your risk rules to define the area you are watching. Do not keep widening it to excuse a failed idea.
A few points can mean very different things in different markets and conditions. The indicator draws a reference price; it does not supply a guaranteed reaction distance.
On your indicator
C1 is the main Call Wall. P1 is the main Put Wall. They mark large gamma readings in the options data. Either area can hold or break; watch the reaction instead of assuming a call wall is always a ceiling or a put wall is always a floor.
Use the latest update and check which option end dates you have selected. Those dates are called expirations. Different selections can produce different levels.
What C, P, Ab, and FLIP measure
Net gamma combines positive and negative readings, allowing them to cancel. C1 has the largest positive net reading; P1 has the most negative. C2 and P2 are the next ranks by size, not necessarily the next prices on your chart.
Ab counts both sides by size before they cancel. FLIP marks a selected change between positive and negative net gamma at nearby strikes, inside the C1–P1 range. It does not prove that every dealer has switched behavior.