# What is the Combo Strike index chart?

The Combo Strikes combine the total Gamma outstanding for the S&P, Nasdaq, and Russell by adding together the impact of each group’s ETF options and Index options to provide you with one value.

To further explain, let’s first look at the x-axis where we have the strike, as compared to the y-axis where we have the amount of Gamma Notional. The strikes for both the SPY and SPX, for instance, capture the Gamma impact from both the Index Options against the SPX and the ETF options against the SPY together. This empowers you to see one view of the total current outstanding Gamma at different strike prices.

When you are trading the S&P complex, or the Nasdaq or Russell, you need to look at these values added together. Positive bars should equate to more call gamma and higher Gamma areas with lower volatility. Negative bars should equate to more put gamma and lower Gamma areas with higher volatility.

Also, if you would like to just see the positions headed into the next expiration, you can choose to look at the Next Expiration button on the upper right hand corner.

The Combo Strikes are a great way to see the largest outstanding Gamma for the S&P, Nasdaq, and Russell complexes, in aggregate, so you know where to expect support and resistance.

SpotGamma Subscribers can access this chart for the SPX, SPY, NDX, QQQ, RUT and IWM.