The Greeks of a position are the partial derivatives of its value with respect to the inputs of the pricing model: delta and gamma ; the vega ; the theta , the change of value with calendar time, all else fixed; the rho ; and the second-order cross-sensitivities vanna , the change of delta with volatility, and volga , the change of vega with volatility.
Ejemplos
Example 4.6 (The desk’s month)
The one-month at-the-money straddle on a share at 100 is worth 4.6059 at 20 volatility and 5.7570 at 25, with zero rates. A desk short 1 000 straddles (multiplier 100) expects to lose , about USD 115 100, when realised volatility comes in at 25. Its vega, 0.2302 per point per straddle, times five points gives nearly the same number: for small changes the expected loss is vega times the volatility gap.