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How Option Gamma and Price Paths Shape Gamma Scalping

Article Quant Q&A · Author: Dice
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Summary

This exchange examines why realized volatility can support profits from a long gamma position and why volatility alone does not determine the result. The questioner understands that scalping requires buying after a decline and selling after a rise, and asks whether larger moves produce more profit when the number of reversals is unchanged. The response emphasizes that option gamma changes with the underlying’s moneyness and with time to expiry. The same realized volatility can therefore produce different gamma scalping outcomes depending on when and where the underlying moves.

Key ideas

  • Gamma scalping profits depend on the path of underlying prices, not only on a realized volatility statistic.
  • Option gamma varies with moneyness and time to expiry, changing the benefit of a given price move.
  • Moves near the strike can have more impact on gamma P&L than moves far from it.
  • A volatility comparison should account for the option’s changing exposure throughout the period.

Tags

OptionsVolatilityDerivatives pricing
Full text
# Interpretation of "realized volatility" in the context of gamma scalping


# Interpretation of "realized volatility" in the context of gamma scalping












I understand that a long gamma position benefits when realized volatility exceeds implied. This benefit manifests in the form of gamma scalping. My confusion is regarding how higher realized volatility directly implies more profit from gamma scalping.

My understanding of gamma scalping is that your pnl increases the more the price of the underlying moves up or down. In order to actually scalp, the price can't just go up, it must go down as well to execute the scalp.

My understanding of realized volatility is that it is the standard deviation of underlying returns - which says nothing about the number of times the asset will actually move up or down, just the magnitude of the move when it does move.

As a result, I don't see why increased realized vol directly translates to increased gamma scalping pnl. Could it be that, if we assume two scenarios, both with the same number of up and down movements, an increase in realized vol will result in bigger movements, which results in higher pnl?

## Answer by user68819 (score 1)

https://quant.stackexchange.com/a/82294

Gamma for an option is not constant at different levels of moneyness and/or over time to expiry. Therefore the gamma pnl from an option is path and 'time of move' dependent.

For example, you can realise 20% when you are 10% away from the strike (very low gamma), you will make very little money trying to scalp this, just as the options have very little gamma.

You could be hovering around atm, in which case your gamma before expiry is very high, in which case you can potentially make a large amount of money.

Also, consider realising a lot of volatility when you have a long time to expiry versus short time to expiry.

Shown in full with attribution under the source's licence. Licence: CC BY-SA 4.0 (Stack Exchange)

This summary was written by Stratmill's research agent from the original; it is not a copy of the source.