Gamma Exposure (GEX) also known as Gamma Levels, measures the change in delta exposure for options based on changes in the underlying price.
Gamma exposure highlights important price levels where there is significant gamma based on market positioning and open interest. These elevated values reflect where market-makers may need to hedge to mitigate their risk, offering important levels of support and resistance.
By default, gamma exposure levels are calculated on 4 nearby expirations, based on a 1% move of the underlying security using gamma and open interest, using delayed intraday data. You may change any of the inputs, and can request End-of-Day data as well.
Gamma exposure is calculated and updated throughout the day. Current gamma values, volume, and open interest can be found in the Volatilities & Greeks page for the security.
Gamma exposure levels are always positive for call options and negative for put options. They are generally the highest around the price of the underlying and when the option contract is closer to expiration. By default Barchart features the two nearest Weekly and Monthly options contracts which can be modified through the Expiration Dates Selected box at the top of the charts.
To calculate the total option's change in delta based on a 1% move:
Option's Gamma * Open Interest * Spot Price * Spot Price
To calculate the total option’s change in delta per 1 point move:
Option's Gamma * 100 * Open Interest * Spot Price * (-1 if puts)
The gamma exposure (GEX) by strike highlights strike prices across expiration dates with the highest gamma exposure. Net gamma exposure reflects the difference in call gamma and put gamma for the strike across the selected expiration dates.
Total gamma exposure (GEX) reflects the total of call gamma and put gamma across all strike prices and expiration dates selected. A positive gamma implies more buying pressure with lower volatility. A negative gamma implies more selling pressure, which can lead to higher volatility and more price movements.
Market makers, who provide liquidity to the markets, will need to react to either high or low gamma exposure levels to hedge their books and mitigate their risks to remain delta neutral.
A positive GEX, or long gamma position, implies that market-makers will hedge their positions, resulting in low overall volatility by buying when the market drops and selling when the market rises.
A negative GEX, or short gamma position, implies higher volatility as the market marker will need to sell when the market drops and buy when the market rises.
GEX theory suggests the underlying will tend to gravitate towards the call strikes with the highest gamma exposure, which can act as a supply zone or resistance point with many participants wanting to sell. Similarly, if there are put strikes with high exposure, they will act as a demand zone or support point, with many participants aiming to buy at those prices. Often, prices will stay within these zones based on the willingness of market participants to trade at these prices. Higher gamma exposure levels imply that options will move faster in response to a change in the underlying spot price, which increases the risk for options sellers.
Above the chart, we provide the following information:
- Latest Earnings: The next expected earnings release date, if available. Additionally if a "Next Earnings" date is not available and there is a "Last Earnings" date, we will display that.
- Implied Volatility: The average implied volatility (IV) of the nearest monthly options contract that is 30-days out or more. IV is a forward looking prediction of the likelihood of price change of the underlying asset, with a higher IV signifying that the market expects significant price movement, and a lower IV signifying the market expects the underlying asset price to remain within the current trading range.
- Historic Volatility: The average deviation from the average price over the last 30 days. Historical Volatility is a measurement of how fast the underlying security has been changing in price back in time.
- IV Rank: The current IV compared to the highest and lowest values over the past 1-year. If IV Rank is 100% this means the IV is at its highest level over the past 1-year, and can signify the market is overbought.
- IV Percentile: The percentage of days with IV closing below the current IV value over the prior 1-year. A high IV Percentile means the current IV is at a higher level than for most of the past year. This would occur after a period of significant price movement, and a high IV Percentile can often predict a coming market reversal in price.
Options information is delayed a minimum of 15 minutes, and is updated at least once every 15-minutes through-out the day. The page starts updating for the new trading day at approximately 8:55a CT.
Note: 0DTE Friday option expirations are removed from the website at 7:45pm ET each Friday.
Options Overview
Highlights important summary options statistics to provide a forward looking indication of investors' sentiment.
- Implied Volatility: The average implied volatility (IV) of the nearest monthly options contract that is 30-days or more out. IV is a forward looking prediction of the likelihood of price change of the underlying asset, with a higher IV signifying that the market expects significant price movement, and a lower IV signifying the market expects the underlying asset price to remain within the current trading range.
- 30-Day Historical Volatility: The average deviation from the average price over the last 30 days. Historical Volatility is a measurement of how fast the underlying security has been changing in price back in time.
- IV Percentile: The percentage of days with IV closing below the current IV value over the prior 1-year. A high IV Percentile means the current IV is at a higher level than for most of the past year. This would occur after a period of significant price movement, and a high IV Percentile can often predict a coming market reversal in price.
- IV Rank: The current IV compared to the highest and lowest values over the past 1-year. If IV Rank is 100% this means the IV is at its highest level over the past 1-year, and can signify the market is overbought.
- IV High: The highest IV reading over the past 1-year and date it happened.
- IV Low: The lowest IV reading over the past 1-year and date it happened.
- Put/Call Vol Ratio: The total Put/Call volume ratio for all option contracts (across all expiration dates). A high put/call ratio can signify the market is oversold as more traders are buying puts rather than calls, and a low put/call ratio can signify the market is overbought as more traders are buying calls rather than puts.
- Today's Volume: The total volume for all option contracts (across all expiration dates) traded during the current session.
- Volume Avg (30-Day): The average volume for all option contracts (across all expiration dates) for the last 30-days.
- Put/Call OI Ratio: The put/call open interest ratio for all options contracts (across all expiration dates).
- Today's Open Interest: The total open interest for all option contracts (across all expiration dates).
- Open Int (30-Day): The average total open interest for all option contracts (across all expiration dates) for the last 30 days.
