Volatility Surface & Derivatives Desk
Arbitrage-Free SVI Volatility Surface Calibration, 0DTE Intraday Gamma-Vanna-Charm Flows, and Index Dispersion Mechanics in 2026
An institutional derivatives desk note detailing Gatheral SVI and SSVI static arbitrage constraints (butterfly and calendar conditions), SPX 0DTE dealer gamma/vanna/charm hedging flows, VIX vs VIX1D variance swap replication, and OCC STANS / Eurex Prisma portfolio margining.
Point clé : SPX 0DTE options account for 51.4% of total S&P 500 options volume ($890B daily notional) in 2026, requiring volatility desks to replace calendar-day time-to-expiry with an activity-weighted intraday variance clock (tau_eff) to prevent wing oscillation.
Dr. Alistair Finch, CQF, FRM