A continuous, STOCHASTIC PROCESS where the market variable (e.g., a COMMON STOCK price or FOREIGN EXCHANGE rate ) exists in continuous time and its probability density function is continuous; the variable changes on a random and continuous basis, and as the time interval becomes larger, uncertainty in the returns increases in a predictable fashion. The diffusion process is widely used in modeling the value of certain financial contracts, such as DERIVATIVES .
Black’s Law Online Dictionary
