请教level 1中有关回报率的一个问题

资金加权收益率&时间加权收益率

资金加权收益率实际是投资的内部收益率

时间加权收益率是每个投资期限收益率的几何平均收益率

时间加权收益率在投资业绩衡量时优于资金加权收益率，因为时间加权收益率不受投资现金流出（withdraw)流入(contribute)的影响.

下面是计算的步骤

1. Determine the timing of each cash flow and whether the cash flow is an inflow (+) or an outflow (-).

2. Net out the cash flows for each period and set the present value of cash inflows equal to the present value of cash outflows.

3. Solve for r to find the money-weighted rate of return. This can be done using trial and error, the IRR function on a financial calculator.

Time-weighted return:
3 steps too!

1. Break the evaluation period into subperiods based on timing of cash flows.

2. Calculate the HPR for each holding period.

3. Take the geometric mean of the annual returns to find the annualized time-weighted rate of return over the measurement period.

关键在于，计算Money-weighted return的时候，实际上求内部收益率，即使得现金流出和流入相等时的一个折现率。

计算Time-weighted return:时候，以现金的流入或流出作为一个划分的点，计算每一个小的时间阶段的收益率，然后再计算几何加权收益率就可以了。

具体内容，请参考内部讲义，或试听本部分课程

感谢胡老师的指导，豁然开朗了

我想请问一下：算出来的money-weighted rate of return 和 time-weighted rate of return 有什么作用？怎么用来衡量portfolio performance？象IRR rule就是accept projects or investments for which the IRR is greater than the oppoortunity cost of capital,但是算出来的money-weighted rate of return 和 time-weighted rate of return是越大越好还是越小越好，还是要和正式的discout rate 做比较？

谢谢！