Gamma exposure
Market makers sell options and hedge them by trading the stock. Gamma exposure (GEX) estimates which way that hedging pushes.
On the dashboard, G−1.2% means the price is 1.2% below the next expiration's gamma flip; G+3.1%, 3.1% above it. The distance is measured from the current price, as a share of it, and updates with every price update.
Why market makers trade the stock
A market maker who sells you an option does not want to bet on the price. To stay neutral, they buy or sell the stock itself, and they adjust that hedge as the price moves. Gamma measures how much the hedge has to change for each move. Added up over all open options, it shows how much stock market makers are likely to trade when the price moves — and in which direction.
Positive and negative
The price where positive turns into negative is the gamma flip. The strikes with the most gamma are the walls.
How it shows on the dashboard
How it is calculated
GEX per strike = gamma × open interest × 100 × price² × 1% Net GEX = call GEX − put GEX
The result is roughly the dollar amount market makers would trade for a 1% move. The standard assumption is that they are long the calls and short the puts that investors hold.
Shown as a share of the ticker's average daily trading: 0.5% means a 2% move forces market makers to trade 1% of a normal day's volume.
Limits
- It is an estimate from open positions, not observed trades. Market makers' real books are not public.
- Open interest is from the previous session, repriced at today's price.
- The dashboard shows the Next expiration; the row popup and the X-Ray show all three.
- The X-Ray prints the selected expiration's net gamma once, as GAMMA in its header. The strike panel's Puts and Calls totals add up each strike's bar and are not that figure.