The Options gamma is best described as a measure of the degree of alterations of the delta of the option. An option’s gamma is stated in the form of a proportion and is a reflection of the alteration of the delta as a response to a single point shift of the underlying stock value.
Just as the delta, the gamma’s continually altering, even with miniscule shifts in the underlying stock value. It normally stays at its highest value during the period when the stock value is in proximity to the strike value of the option. It drops with the option going deeper into / out of the money. Every option that’s severely deeply into / out of the money is characterized by a gamma value that is in close proximity to 0.
As an example, we take a stock XYZ, which is presently trading at $47, and for which there’s a FEB 50 call option up for sale for $2 and we presume that its delta is 0.4 and its gamma is 0.1 /10 %. In the event of an increase in stock price by $1 to a rate of $48 the delta is going to be regulated in the upward direction by 10 % to 0.5 from 0.4.
On the other hand, on the stock trading in the downward direction by $1 to a rate of $46 the delta is going to experience a 10% drop to 0.3.
The passing of time and how it effects the gamma
With the time left for expiration becoming less, at-the-money Options Gamma increases while in-the-money as well as out-of-the-money options’ gamma decreases.
On venturing online, you will find charts depicting the behaviour of gamma of options at several strikes expiring in several time periods that also has the rate at which the stock is presently trading.
Alterations in volatility/instability and how it effects gamma
During the period of low volatility, at-the-money options’ gamma is high whereas the deeply into /out-of-the-money options’ gamma move towards 0. The reasoning behind this phenomenon is that during the period of low volatility, the time worth/value of such options happen to be low. However, it rises intensely with the underlying stock value approaching the strike price.
During the period of high volatility, gamma is inclined to be constant across the entire strike prices. The reasoning behind this phenomenon is that during the period of high volatility, deeply in/out-of-the-money options’ time value happen to already be quite extensive. Consequently, the rise in such options’ time value as they move closer to the money is going to be less theatrical, which explains the low and constant gamma.
Online, you will find charts illustrating the relationship that the option’s gamma has with the volatility/instability of the underlying security and the value at which the security is trading a share.