COR1M is a 1-month implied correlation metric that measures how closely individual stocks are moving together relative to the index. It reflects the degree to which single-stock movements are being driven by broad market forces versus their own fundamentals or options positioning.

What the readings mean

• Low COR1M — stocks are trading independently of each other and the index. Options-driven hedging flows on individual names are more likely to influence their price action. This is the environment where SpotGamma's gamma levels on single stocks tend to be most reliable.
• High COR1M — stocks are moving together, typically driven by macro or index-level selling. When correlation spikes, individual gamma levels matter less because broad market flows override single-stock dynamics.

Connection to the Dispersion Trade

The dispersion trade exploits the relationship between index volatility and single-stock volatility. The classic expression is: short index implied volatility (e.g. SPX options), long implied volatility on individual constituents. When correlation is low, single stocks move independently and the index vol tends to be cheap relative to its components — making the dispersion trade attractive. When correlation rises and everything moves together, the trade unwinds.

Large dispersion positioning can show up in SpotGamma's HIRO and Synthetic OI data as unusual call/put activity spread across many single names simultaneously, often with index volatility moving in the opposite direction.

Where to watch it

COR1M and correlation context are discussed regularly in the Founder's Note. Brent uses low-correlation environments as a signal that the options-driven gamma framework applies cleanly, and flags correlation spikes as a reason to reduce reliance on individual gamma levels until the macro pressure subsides.

SpotGamma Essentials and Alpha subscribers can access the Founder's Note here.