问题如下：
Which of the following statements about using a risk factor-based approach rather than a mean–variance-optimization technique is correct?
Statement 1 Risk factor-based approaches to asset allocation produce more robust asset allocation proposals.
Statement 2 A mean–variance optimization typically overallocates to the private alternative asset classes due to stale pricing.
选项：
A.Only Statement 1
Only Statement 2
Both Statement 1 and Statement 2
解释：
C is correct.
Statement 1 is correct because risk factor-based approaches to asset allocation can be applied to develop more robust asset allocations. Statement 2 is correct because a mean–variance optimization typically overallocates to the private alternative asset classes, partly because of underestimated risk due to stale pricing and the assumption that returns are normally distributed.
对于第二个statement，还是想多问一下。
题目题干是use “risk factor-based approach”而不是用“MVO”的statement，按照这个思路，为什么statement 2 是MVO独有的缺点呢？我理解，risk-factor based方法也是基于历史数据，在对private alternative asset classes是不是也只能采用到stale pricing的smoothed data，因此，的出来也会overallocate to private alternative asset classes？
如此一来，是不是statement 2其实是两种方法共同的缺点吗？
请教下我哪里思考的不对吗？
