TY - JOUR AU - Engle,Robert F. AU - Rosenberg,Joshua V. TI - GARCH Gamma JF - National Bureau of Economic Research Working Paper Series VL - No. 5128 PY - 1995 Y2 - May 1995 UR - http://www.nber.org/papers/w5128 L1 - http://www.nber.org/papers/w5128.pdf N1 - Author contact info: Robert F. Engle, III Department of Finance, Stern School of Business New York University, Salomon Center 44 West 4th Street, Suite 9-160 New York, NY 10012-1126 Tel: 212/998-0710 Fax: 212/995-4220 E-Mail: rengle@stern.nyu.edu AB - This paper addresses the issue of hedging option positions when the underlying asset exhibits stochastic volatility. By parameterizing the volatility process as GARCH, and utilizing risk- neutral valuation, we estimate hedging parameters (delta and gamma) using Monte-Carlo simulation. We estimate hedging parameters for options on the Standard and Poor's 500 index, a bond futures index, a weighted foreign exchange rate index, and an oil futures index. We find that Black-Scholes and GARCH deltas are similar for all the options considered, while GARCH gammas are significantly higher than BS gammas for all options. For near the money options, GARCH gamma hedge ratios are higher than BS hedge ratios when hedging a long term option with a short term option. Away from the money, GARCH gamma hedge ratios are lower than BS. ER -