请问一级习题集第507、528、561看不懂答案 574为何mean renversion，naturel gas parices are negatively correlated。 584如何判定gamma正负，图像gamma无论in at or out of the money不是永远为正吗？

老师您好。计算BCVA时，CVA和DVA都要乘以前一年的存活率，那么如果考试要求单独算一个公司承担的CVA，还要不要乘以该公司前一年的存活率？

Your supervisor is an expert in market and credit risk. He recruits you to manage the operational risk department. He would like to use VaR to measure the firm's operational risk and proposes that you use the same VaR framework previously developed for market and credit risk. Which of the following is a valid argument for why it is difficult to estimate an operational VaR using the same framework as market and credit VaR? A.Market risk events are easier to map to risk factors than operational risk events. C.Market and credit VaRs are estimated using only frequency distribution, but operational VaR is estimated using both a freq distribution and a severity distribution. 其他B,D肯定错，但是不明白为什么C错和A对，为什么market risk更容易map to risk factors? 请老师解答一下，谢谢！

老师，这个第45题中，为什么不需要考虑duration？谢谢。

选项D中的credit conversion factors (CCF)是指什么？ 以及答案解析中针对dubious assumption如何理解

老师，这个题中，md应该与y也有关啊。为什么让md相同再判断dv01？

老师，四个选项分别如何解释

老师，这个题怎么解释

Advanced Internal Rating Based Approach中 WCDR的表达式中有ρ，那么ρ和哪一种风险有关(market risk? credit risk? interest risk属于market risk), 即这道题的D选项为什么不对? 还有一种想法，loan的interest risk属于market risk, 根据题目，这家bank也对market risk进行了measure, 这没有ignore吧

Advanced Internal Rating Based Approach中 WCDR的表达式中有ρ，那么ρ和哪一种风险有关(market risk? credit risk? interest risk属于market risk), 即这道题的D选项为什么不对? 还有一种想法，loan的interest risk属于market risk, 根据题目，这家bank也对market risk进行了measure, 这没有ignore吧