Derivatives • Options
Options Greeks & Market Maker Gamma Hedging (0DTE)
Delta, Gamma, Vega, Theta dynamics, positive vs. negative gamma regimes, and how 0DTE options dictate intraday price discovery.
Author: CMD Wire Institutional Research
Updated: August 2026 • 7 min read
1. The Options Greeks Defined
The price sensitivity of an options contract to underlying market variables is measured by the Options Greeks:
| Greek | Sensitivity Variable | Market Definition |
|---|---|---|
| Delta (\Delta) | Underlying Stock Price | Rate of change of option price per $1 move in underlying asset. |
| Gamma (\Gamma) | Delta Acceleration | Rate of change of Delta per $1 move in underlying asset. |
| Vega ( u) | Implied Volatility | Option price change per 1% change in implied volatility. |
| Theta ( heta) | Time Decay | Option value loss per elapsed calendar day. |
2. Market Maker Gamma Regimes
Market makers who sell options to retail and institutional traders must hedge their directional exposure in the underlying stock/futures market:
- Positive Gamma Regime (Long Gamma): Market makers buy dips and sell rips to re-hedge delta, acting as a volatility dampener that pins prices in narrow trading ranges.
- Negative Gamma Regime (Short Gamma): Market makers must sell when prices fall and buy when prices rise, aggressively accelerating market crashes and melt-ups.
3. The Rise of 0DTE Options
With same-day expiring Zero-Day-to-Expiration (0DTE) options accounting for over 50% of total S&P 500 options volume, Gamma concentration at at-the-money strikes generates massive intraday dealer hedging flows that can reverse or accelerate daily market momentum in minutes.