What pros do
Market makers sell calls, get negative delta, must buy futures to stay neutral. Gamma forces re-hedge as S moves. Vanna forces re-hedge when implied vol moves (even with S flat). 60% of S&P futures volumes = dealer hedging, not directional conviction. October 2024 phantom crash: pure gamma move from over-hedged dealers selling futures in 10 minutes.
Learn it
FX Traders vs Brokers CH13-18 (theory) + CH19-24 (dealer hedging). Derivatives Trading by Djellal Djouad ($60/month): Bloomberg Pro Terminal + live options flow + daily briefings.