NO.PZ2020011303000054
问题如下:
A one-year project has a 3% chance of losing USD 10million, a 7% chance of losing USD 3 million, and a 90% chance of gaining USD 1 million.
Suppose that there are two independent identical investments with the properties.
What are (a) the VaR and (b) the expected shortfall for a portfolio consisting of the two investments when the confidence level is 95% and the time horizon is one year?
选项:
A.VaR = USD 6 million, ES = USD 9.534 million
B.VaR = USD 9 million, ES = USD 9.534 million
C.VaR = USD 9 million, ES = USD 13 million
D.VaR = USD 6 million, ES = USD 13 million
解释:
有一个项目,3%的概率会损失10m,7%损失3m,90%概率会获得1m,假设这俩投资都是独立相同的,求95%置信区间下1年的VaR和ES?
Losses (USD) of 20, 13, 9, 6, 2, and −2 have probabilities of 0.0009, 0.0042, 0.054, 0.0049,
95%ES=[0.0009×20+0.042×13+(0.05-0.0009-0.0042)×9]/0.05=9.534
10-1 和-1 10 概率一共是3%*90%*2=0.54。
我理解答案用 5%-0.0009-0.0042 是要在VAR线以上算剩余的概率,相当于线性插值法么?
但是为什么这个是配给-9呢?而不是 用5%-0.54-0.0042配给-13,或者5%-0.54-0.0009配给-20。
此外,这也带来我另一个问题,VAR 95%的话,题目中不是正好95%,而是差一些,这时候的处理方式是什么?