SpotGamma
SpotGamma

@spotgamma

5 Tweets 7 reads Dec 07, 2021
The "Gamma Trap"
Dec SPX has 3.3mm puts which is the largest of any expiration.
The chunkiest of these puts are likely held by funds which will hold to 12/17 expiration.
The 4000 strike has the most put interest.
If the market goes under 4500, the gamma trap could set:
(1/n)
A declining market means dealers have more futures to sell in order to hedge those existing puts. This fuels volatility like pushing a ball down a hill. Furthermore implied volatility rises, increasing put values, requiring larger hedges.
Dealer selling leads to faster market declines, which brings more selling (ex: margin calls). The fear brings out more put buying. Implied volatility goes even higher. Dealers have to sell more futures to hedge both new puts positions & existing positions.
The "trap" is this reflexive feedback loop of dealer selling â†Šī¸
which leads to put buying and more liquidations â†Šī¸
which leads to more put buying â†Šī¸
which leads to more dealer selling.
Then, suddenly, on 12/17 those 3.3 million puts expire. Dealers find themselves short too many futures, and needing to cover ASAP. Trap released. Markets rally.
Consider 2 other major lows coinciding with the day after OPEX:
Dec 24th, 2018
March 23rd, 2020

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