Net gamma measures how market makers must hedge as price moves. Negative gamma: dealers hedge into moves — selling as price falls, buying as it rises — which amplifies volatility. Positive gamma: dealers hedge against moves, which dampens volatility and pins price toward high-OI strikes. Max pain is the strike where the most option value expires worthless. Computed from each ticker's live options chain at scan time — data-freshness provenance, not a predictive claim.