最常见的是balanced portfolio, i.e. 有equity, bonds 等等。然后investment firm就要有balanced composite的 performance presentation 现在investment firm,想把balanced portfolio里面的某种成分挖出来(carve out)单独present performance results,比如equity部分(等于把equity 部分的performance从综合的portfolio里面单独弄出来)这个时候就是需要涉及cash allocation了 as if the carved-out part were separately managed with its own cash cusion