Interpreting Up-Gamma and Down-Gamma Exposure
Summary
The document describes up-gamma as the change in an option position’s delta when the underlying rises, and down-gamma as the corresponding sensitivity when it falls. The answer interprets a position that is long up-gamma and short down-gamma as gaining convexity during rallies while becoming less sensitive to declines, which it says can dampen losses.
The explanation is intuitive rather than a payoff analysis: it provides no position structure, pricing assumptions, or plotted profit-and-loss profile. The question itself raises the possibility that more information is needed to visualize the result, and the examples mentioned do not resolve that ambiguity. The claimed downside limitation should therefore not be read as a general guarantee that losses are capped.
Key ideas
- Up-gamma describes delta sensitivity to increases in the underlying price, while down-gamma describes sensitivity to decreases.
- Long up-gamma is associated with increasing convexity as the underlying rises.
- The response interprets short down-gamma as dampening sensitivity to falling prices.
- A complete profit-and-loss profile requires more information about the position and its assumptions.
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Full text
# P/L of a position described in terms of Up-Gamma and Down-Gamma # P/L of a position described in terms of Up-Gamma and Down-Gamma I can't visualize the profit/loss of a position described in terms of its Up-Gamma and Down-Gamma. The question arise from pag. 193 of Dynamic Hedging by Taleb. How would you describe a position that is long up-gamma and short down-gamma in terms of profit and loss? How the signs of the up-gamma and down-gamma affect the position? My idea: P/L increases "more than linearly" if the underlying price increase thanks to the positive effect of positive and greater value of up-gamma (long up-gamma). The P/L are affected positively by smaller value of down-Gamma, possibly negative values, that implies a P/L where the losses are "capped". Edit My second interpretation is that "short" Down-Gamma only means that the Down-Gamma of the position is negative. If I am right, this is coherent with a risk reversal but not with a diagonal ratio spread, the two examples presented by the author. Or it could be coherent provided that the P/L is concave when the asset price is declaning. Basically, to visualize the P/L more information is required is my opinion. If I am not clear, please, let me know. Thanks for the help. ## Answer by Mahavir Bhattacharya (score 0) https://quant.stackexchange.com/a/79906 Your understanding is spot on! Just elaborating more, basis my understanding. Up-Gamma denotes the rate of change of an option's Delta in response to increases in the underlying asset's price. A portfolio that is long Up-Gamma benefits from rising prices as its Delta becomes more sensitive, amplifying potential profits. This characteristic allows for gains that escalate "more than linearly" with underlying price increases, reflecting a positive convexity in the profit profile. Conversely, Down-Gamma measures the rate of change of Delta when the underlying price decreases. A position that is short Down-Gamma mitigates losses in declining markets by reducing Delta sensitivity as prices fall. This dampens the impact of downward movements on the portfolio's value, effectively capping potential losses. Combining a long Up-Gamma position with a short Down-Gamma position creates a strategy that balances these dynamics. Such a strategy benefits from both increased profit potential during market rallies and reduced downside risk during downturns. This strategic approach is favored in volatile markets where price swings are more pronounced. It provides you with a structured framework to optimize risk-adjusted returns, leveraging the dual benefits of positive convexity during bullish phases and downside protection during bearish phases.
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