大家好,我现在在美国留学,在准备考CFA。刚注册这个论坛,希望能向大家学习。以下是我遇到的几个问题,还请不吝赐教。
PS: 我的qq是1214877519,有兴趣讨论的同学我们也可以用qq联系。
1. 请问single-name CDS的payoff为什么是“based on the market value of the cheapest-to-deliverbond that has the same seniority as the reference obligation”?为什么不是具有相同seniority的所有bonds的market values的平均值?
2.Study Notes在讲完CDS spread的计算方法之后,马上又说了一句:“We can also quote the CDS price as: price of CDS (per$100 notional) = $100 - upfront premium。”
在我的印象当中,我一直以为在买卖CDS的当时,买卖双方只支付upfront premium(如果这是个正数,则买方付给卖方;如果是负数,则卖方付给买方);而在买卖完成之后,则是买方给卖方支付CDS coupon。所以我不理解为什么还需要引入这个“CDS price”的概念?这个“CDS price”是哪一方付给哪一方的?是在买卖CDS的当时还是买卖之后支付的?
3. Supposethat the process followed by the underlying stock price in a risk-neutral worldis
dS =u*S*dt + sigma*S*dz,
wheredz is a Wiener process, u is the expected return in a risk-neutral world, and sigmais the volatility. To simulate the path followedby S, we can divide the life of the derivative into N short intervals of lengthDelta_t and approximate the above equation as
S(t +Delta_t) - S (t) = u*S(t)*Delta_t + sigma*S(t)*epsilon*SquareRoot(Delta_t),
whereepsilon is a random sample from a standard normal distribution.
我想确认一下:这里之所以用根号Delta_t,是为了保证sigma*S(t)*epsilon*SquareRoot(Delta_t)的方差约等于sigma*S*dz的方差,对吗?