问题如下图：
选项：
A. 
B. 
C. 
解释：
请问这道题的问题是什么意思，没有理解。谢谢
海胆君 · 2019年05月06日
这道题是让你通过表格里俩个portfolio的weight来推测，他是用哪种方法进行配比的。
从对比来看，AA有明显的concentration的现象，而这也是MVO方法的一个显著缺点。
书上讲课逻辑就是先介绍了MVO方法，然后提出了MVO的多个缺点，并针对每个缺点提出了1-2个解决办法。其中，针对集中度缺点提出的解决办法，就是reverse O和BL方法。
因此如果假设AA用了reverse O和BL的话，那他不可能配比上还存在concentration的问题，进而只能选A。
reverse O是一上来用整个市场value-weighted来反求return，整个市场是不会集中的，只可能大value占比高，不会存在小value配比0的情况吧？
BL是在reverse O基础上，增加了manager自己对于配比的想法，既然本身已经是市场value-weighted求出来的了，即使加上了自己想法也不可能倒推至题目这样极端的集中度配比。
MegBea anHanna Müller are senior analysts for a large, multi-visionmoney management firm. Bea supports the institutionportfolio managers, anMüller es the same for the private wealth portfolio managers. Bea reviews the asset allocation in Exhibit 1, rivefrom a mean–varianoptimization (MVO) mol for institutionclient, noting thtails of the MVO are lacking. Exhibit1 Asset Allocation anMarket Weights(in percent) The asset allocation in Exhibit 1 most likely resultefrom a mean–varianoptimization using: historictreverse optimization. Black–Litterminputs. A is correct. The allocations in Exhibit 1 are most likely from MVO mol using historicta inputs. MVO ten to result in asset allocations thare concentratein a subset of the available asset classes. The allocations in Exhibit 1 have heavy concentrations in four of the asset classes anno investment in the other four asset classes, anthe weights ffer greatly from globmarket weights. Compareto the use of historicinputs, the Black–Littermanreverse-optimization mols most likely woulless concentratein a few asset classes anless stant from the globweights. 可以大概讲一下B\C的方法的原理吗
这是因为投资的资产过于集中而判断是mvo吗？
