Large institutional positions often move through the options market, and they leave footprints: volumes that break the norm, concentrated expirations, premiums that spike. Following that unusual options activity can anticipate moves before they show up in price.
The challenge is that most flow alerts are noise. Cortex cross-references unusual activity with price, volume and regime, so the signal arrives with context rather than as an isolated alarm.
The goal isn't to chase every large trade, but the ones that matter within a coherent picture.