Instruments I have prices and cash flows at trading times T. Market: prices X_t, cash flows C_t taking values in \RR^I.

Every arbitrage-free model is paramterized by a \RR^I-valued martingale (M_t) and positive adapted measures (D_t). X_t D_s = M_t - \sum_{s\le t} C_s D_s

B-S/M is M_t = (r, se^{\sigma B_t - \sigma^2 t/2})P and D_t = e^{-\rho t}P, where P is Wiener measure on \Omega = C([0,\infty)) and B_t(\omega) = \omega(t) is standard Brownian motion.