NO.PZ2019012201000031
问题如下：
Initially, Fund TMT held active positions in two real estate stocks—one was over-weighted by 1 %, and the other was under-weighted by 1%. Fund TMT traded back to benchmark weights on those two stocks. Then, TMT selected two different stocks that were held at benchmark weights, one automobile stock and one technology stock. TMT over-weighted the automobile stock by 1% and underweighted the technology stock by 1%. What was the effect of TMT’s two trades on its active share? TMT’s active share:
选项：
A.decreased.
B.remained unchanged.
C.increased.
解释：
B is correct.
考点：Active Share and Active Risk
解析：只有当投资组合的主动权重绝对值的总和发生变化时，主动份额才会发生变化。在TMT基金的两笔交易中，初始头寸和新头寸都涉及两只股票，一只减持1%，另一只增持1%，因此主动权重绝对值的总和没有变化，所以主动份额并没有改变。
如题，这两道题的题目预设几乎一样，都是将同行业的股票比重差别（ overweight和underweight的股票情况）变为不同行业的。那么这种情况下，基础班P140有个结论是Higher active risk tend to have higher Active Share，李老师的解读也是高active risk必然对应高active share，即使不同步变动，也是active risk大active share小，见下图。
但是看到这两个题目，同样的情况下，active risk增加了active share却不变，那岂不是有矛盾？
