Zomma is a third-order risk measure of the degree to which the gamma of an options contract is sensitive to changes in implied volatility. It is also referred to as "D-gamma/D-vol." Gamma itself is a second-order risk measure of an option's sensitivity of its delta to changes in the underlying price.

Zomma is part of a category of measurements used to assess the price sensitivity of a derivative to various factors, such as changes in interest rates, volatility, or the spot price of the derivative's underlying asset. These measurements are commonly referred to as "Greeks" because they are denoted by Greek symbols; however, the word "zomma" was made up by traders to sound like a Greek letter and is not part of the Greek alphabet.