the book is correct

精神可嘉,认真

高峰值 (k>3) 对应厚尾啊。。

http://baike.baidu.com/view/634985.htm
百科上说，K大于3，比正态分布陡，反之则平坦。。。书上K大于3的时候明显比正态分布扁啊。。

Normal-distributed returns have a kurtosis of 3, irrespective their mean or standard deviation. Distributions with kurtosis of 3 are said to be mesokurtic. If a distribution’s kurtosis is greater than 3, it is said to be leptokurtic. If its kurtosis is less than 3, it is said to be platykurtic. Leptokurtosis is often associated with distributions that are simultaneously “peaked” and have “fat tails.” Platykurtosis is often associated with distributions that are simultaneously "less peaked" and have "thinner tails".