随机游走模型假设各时期的收益率是独立的，并且不同时期的收益率的分布是相同的。为了更形象的理解随机游走模型，想想轮盘赌的转盘上表明了各种不同的收益率，每一期转动轮盘，就可以会根据轮盘上的标注获得下一期相应的收益。但每次转动轮盘的结果间是没有联系的，所以过去的收益率和未来的收益率是不相关的。但是由于每次转动的轮盘是相同的，所以各轮的收益率都服从相同的分布。-Random walk model assumes that the yield is independent of each period, and the distribution of the yield of different periods are the same. To better understand the image of a random walk model, think on the roulette wheel show a variety of different yields for each of the rotating wheel, it can be obtained in accordance with the corresponding period of the next earnings mark on the wheel . But among the results of each wheel rotation is not linked, so past and future earnings yield rate is irrelevant. However, due to the rotation of each wheel is the same, so the yield of each of the wheels are subject to the same distribution.