下面的 dA/dB 都是 A对B求偏导的意思。
black-scholes equation:
dV/dt + 1/2 σ^2S^2d^2V/d^2S + rS dV/dS - rV = 0
对S求偏导:
d^2V/dtdS + σ^2Sd^2V/d^2S + 1/2 σ^2S^2d^3V/d^3S+ rdV/dS+ rS d^2V/d^2S- rdV/dS = 0
d(dV/dS)/dt + 1/2 σ^2S^2d^2(dV/dS)/d^2S + (σ^2S +rS)d(dV/dS)/dS = 0
代入delta=partial V / partial S:
dΔ/dt + 1/2 σ^2S^2d^2Δ/d^2S + (σ^2S +rS)dΔ/dS = 0