A Goal Seeking Investment Model
提出一个基于Wiener过程的概率投资模型，分析方差和时间跨度对实现投资目标的影响，发现高方差有时反而有利，且足够长的时间跨度几乎总能实现目标。
A probabilistic investment model is formulated as a Wiener process with a barrier. A planning horizon, targeted rate of return, discount rate, and the mean and variance rate of return are the important parameters in the model. Sensitivity analyses are studied. Several significant statements can be made: (1) contrary to traditional mean-variance portfolio models, rate of return variance may not always be an undesirable characteristic, since higher variance can increase the chances of achieving certain types of investment goals; (2) one can almost always achieve certain types of investment goals if the time horizon is sufficiently long.