请问这题为什么这样算？而不是求一年的95%的var?
问题如下图：
选项：
A. 
B. 
C. 
D. 
解释：
Consir the following information. You have purchase10,000 barrels of oil for livery in one yea priof $25/barrel. The rate of change of the priof oil is assumeto normally stributewith zero meanannuvolatility of 30%. Margin is to paiwithin two ys if the cret exposure becomes greater th$50,000. There are 252 business ys in the year. Assuming enforceability of the margin agreement, whiof the following is the closest number to the 95% one-yecret risk of this governeunr the margining agreement? $50,000 $58,000 $61,000 $123,000 ANSWER: C The worst cret exposure is the $50,000 plus the worst move over two ys the 95% level. The worst potentimove is ασT=1.645×30%×2252=4.40%\alpha\sigma\sqrt T=1.645\times30\%\times\sqrt{\frac2{252}}=4.40\%ασT =1.645×30%×2522 =4.40%. Applieto the position worth $250,000, this gives a worst move of $10,991. Aing this to $50,000 gives $60,991. 题目问whiof the following is the closest number to the 95% one-yecret risk 既然是问的one year的cret risk，为什么求Var的时候要转换成有两天敞口的呢？
老师好，我不太明白这里的实际操作。意思是我买了一个futures，一年后25 块钱买10，000桶油。标的物价值250，000然后如果油价下跌到20以下，我要交保证金，就是说我的potentiloss 超过50，000的时候，我开始交保证金。然后我的cret risk ，如果以worst case 衡量，来自于这50，000（这个明白） + “worst move over two ys 95% level”（这里不明白）其实我尤其不明白的是我亏钱的时候交margin，作为有损失的一方，我面临的是什么cret risk？
根号T里面的那个2是怎么回事呀
为什么要加上50000？
10991为啥要加上50000？？
