请教各位高手为什么上证50里面的有些好股量缩的那么厉害

份额规模变动详情净资产规模变动详情[淘股吧]
日期 期间申购（亿份） 期间赎回（亿份） 期末总份额（亿份） 总份额变动率
2015-07-23 --- --- 82.22 ---
2015-07-22 --- --- 84.90 ---
2015-07-21 --- --- 86.59 ---
2015-07-20 --- --- 88.14 ---
2015-07-17 --- --- 91.62 ---
2015-07-16 --- --- 92.80 ---
2015-07-15 --- --- 94.75 ---
2015-07-14 --- --- 96.42 ---
2015-07-13 --- --- 101.96 ---
2015-07-10 --- --- 106.14 ---
2015-07-09 --- --- 111.15 ---
2015-07-08 --- --- 120.11 ---
2015-07-07 --- --- 128.25 ---
2015-07-06 --- --- 119.62 ---
2015-07-03 --- --- 85.48 ---
2015-07-02 --- --- 59.94 ---
2015-07-01 --- --- 51.93 ---
2015-06-30 274.31 287.97 58.46 -18.94%
2015-06-29 --- --- 43.08 ---
2015-06-26 --- --- 35.46 ---
2015-06-25 --- --- 32.94 ---
2015-06-24 --- --- 33.