“…In fact, quite a lot of observed natural and social phenomena, such as the fluctuation of stock price and the rate of return in Financial markets, exhibit properties of "biased random walk" and "decile-shaped fat tail". It is suggested that fractional Brownian motion (fBm) with H ∈ (0, 1/2) ∪ (1/2, 1)(see [2,7,8,14]), which owns the self-similarity and the long-term memory, provides better modeling and description of such phenomena. In particular, such fractional equations are simple and effective, which were discussed early in [1,17,27,31].…”