债券定价及利率风险的市场价格的重构方法

假设利率变化的模型是由随机微分方程给出,则可以用推导Black-Scholes方程的方法来推出债券价格满足的偏微分方程,得到一个抛物型的偏微分方程.但是,在债券定价的方程中隐含有一个参数λ称为利率风险的市场价格.所谓债券定价的反问题,就是由不同到期时间的债券的现在价格来得到利率风险的市场价格.对随机利率模型下债券定价的正问题先给予介绍和差分数值求解方法,并介绍了反问题,且对反问题给出了数值方法.     

混合模型下具有动态违约边界的债券定价

在混合模型下,研究了具有动态违约边界的公司债券定价问题.首先利用风险中性定价原理建立此定价问题的数学模型.然后,应用函数代换技巧和偏微分方程镜像法给出模型的显式解.最后,通过一个算例分析动态违约边界对公司债券价格的影响.结果表明:通过调整违约边界的相关参数值,可以得到不同形状的债券价格曲线,进而控制风险或得到更高的债券收益率.     

考虑可违约风险资产的风险敏感度投资决策问题

讨论了资产价格在宏观经济以及金融等因素影响下,含有可违约风险债券的连续时间风险敏感度投资决策问题.运用随机控制与随机分析理论,得到了最优投资决策存在的一个充分条件,并在一定条件下解得最优投资决策遵循一个关于因素水平以及债券违约概率的代数方程,对于数值计算有较好的实用性以及可操作性.     

结构转换条件下债券期权定价研究

从利率动态变化、结构转换和期权定价三个方面进行分析,对结构转换下的债券和债券期权进行定价,考虑了结构转换对利率衍生物定价的影响,利用Ito引理获得债券定价的偏微分方程,并得到债券期权定价的特征函数与递归等式.结构转换下债券期权定价的灵敏度分析表明期权价值与初始状态概率、结构的持续性和结构波动率有关.     

含有信用风险的跳扩散市场的最优组合选择

假定投资者将其财富分配在这样两种风险资产中,一种是股票,价格服从跳跃扩散过程;一种是有信用风险的债券,其价格服从复合泊松过程.在均值-方差准则下通过最优控制原理来研究投资者的最优投资策略选择问题,得到了最优投资策略及有效边界,最后通过数值例子分析了违约强度、债券预期收益率以及目标财富对最优投资策略的影响.     

关于巨灾债券定价模型的研究

巨灾债券的定价是巨灾债券的核心技术及难题。本文从两个方面来分析巨灾债券的定价:首先从规范学的角度来分析巨灾债券的定价,以金融衍生品的无套利定价方法确定巨灾债券的价格,即"巨灾债券价格应该为多少";其次,从实证学角度分析巨灾债券的定价,以利用精算学中的Wang变换和双因素变换模型为定价方法,分析巨灾债券的价格,即"巨灾债券价格是多少",通过对实际巨灾债券的价格实证分析得到:双因素模型能更好的拟合实际价差,对单一事件单一期限的巨灾债券,运用双因素模型得到较高的拟合优度。     

多尺度亚式期权定价模型的奇摄动解

讨论了一类多尺度亚式期权定价随机波动率模型问题,其中随机波动率采用了具有快慢变换的随机波动率模型.通过Feynman-Kac公式,得到了风险资产期权价格所满足的相应的Black-Scholes方程,运用奇摄动渐近展开方法,得到了期权定价方程的渐近解,并得到其一致有效估计.     

一种特殊重置期权的定价

在完全市场环境下,对文献所介绍的创新的重置期权,在幂型支付的情形下,当债券价格B（t）为时间t的确定性函数时,以鞅论和随机分析为数学工具得到了其定价公式.     

连续时间下的可分离债券的定价

假设股票价格服从对数正态分布,且股票价格的波动率,无风险利率均为时间的确定性连续函数,利用鞅的方法研究了连续时间下的可分离债券的定价,并得到了可分离债券的定价公式.     

跳-扩散结构下内含巴黎期权特征的可转债定价研究

考虑了跳-扩散结构下的可转换债券定价问题.首先分析了回售、赎回等条款,发现可转换债券具有巴黎期权特征.然后,根据期权定价理论,运用近似对冲跳跃风险的方法,建立了可转换债券的定价模型,得到了可转换债券价格所满足的偏微分方程.基于半离散化方法,给出了偏微分方程求解的数值方法,并且对数值方法的稳定性和误差进行了分析.最后,以重工转债和南山转债为例,对可转债市场进行了实证研究.     

违约强度由Lévy从属过程驱动的约化信用风险模型及信用违约互换的定价

本文引入一个约化信用风险模型,其中违约强度定义为从属过程,即非负增Lévy过程.用概率方法得到了违约时间分布的解析表达式.利用该解析表达式,给出了该信用风险模型下的信用违约互换(Credit Default Swaps)的闭形式的定价公式.     

Pricing Defaultable Bonds in a Markov Modulated Market

We address the problem of pricing defaultable bonds in a Markov modulated market. Using Merton's structural approach we show that various types of defaultable bonds are combination of European type contingent claims. Thus pricing a defaultable bond is tantamount to pricing a contingent claim in a Markov modulated market. Since the market is incomplete, we use the method of quadratic hedging and minimal martingale measure to derive locally risk minimizing derivative prices, hedging strategies and the corresponding residual risks. The price of defaultable bonds are obtained as solutions to a system of PDEs with weak coupling subject to appropriate terminal and boundary conditions. We solve the system of PDEs numerically and carry out a numerical investigation for the defaultable bond prices. We compare their credit spreads with some of the existing models. We observe higher spreads in the Markov modulated market. We show how business cycles can be easily incorporated in the proposed framework. We demonstrate the impact on spreads of the inclusion of rare states that attempt to capture a tight liquidity situation. These states are characterized by low risk-free interest rate, high payout rate and high volatility.     

Credit Derivatives Pricing Based on Lévy Field Driven Term Structure

We use Lévy random fields to model the term structure of forward default intensity, which allows to describe the contagion risks. We consider the pricing of credit derivatives, notably of defaultable bonds in our model. The main result is to prove the pricing kernel as the unique solution of a parabolic integro-differential equation by constructing a suitable contractible operator and then considering the limit case for an unbounded terminal condition. Finally, we illustrate the impact of contagious jump risks on the defaultable bond price by numerical examples.     

Time-consistent mean–variance proportional reinsurance and investment problem in a defaultable market

In this paper, we consider an optimal time-consistent reinsurance-investment problem incorporating a defaultable security for a mean–variance insurer under a constant elasticity of variance (CEV) model. In our model, the insurer’s surplus process is described by a jump-diffusion risk model, the insurer can purchase proportional reinsurance and invest in a financial market consisting of a risk-free asset, a defaultable bond and a risky asset whose price process is assumed to follow a CEV model. Using a game theoretic approach, we establish the extended Hamilton–Jacobi–Bellman system for the post-default case and the pre-default case, respectively. Furthermore, we obtain the closed-from expressions for the time-consistent reinsurance-investment strategy and the corresponding value function in both cases. Finally, we provide numerical examples to illustrate the impacts of model parameters on the optimal time-consistent strategy.     

具有共同冲击相依性的跳扩散金融市场中有着延迟和违约风险的鲁棒最优再保险和投资策略

在本文中,我们考虑跳扩散模型下具有延迟和违约风险的鲁棒最优再保险和投资问题,保险人可以投资无风险资产,可违约的债券和两个风险资产,其中两个风险资产遵循跳跃扩散模型且受到同种因素带来共同影响而相互关联.假设允许保险人购买比例再保险,特别地再保险保费利用均值方差保费原则来计算.在考虑与绩效相关的资本流入/流出下,保险公司的财富过程通过随机微分延迟方程建模.保险公司的目标是最大程度地发挥终端财富和平均绩效财富组合的预期指数效用,以分别研究违约前和违约后的情况.此外,推导了最优策略的闭式表达式和相应的价值函数.最后通过数值算例和敏感性分析,表明了各种参数对最优策略的影响.另外对于模糊厌恶投资者,忽视模型模糊性风险会带来显著的效用损失.     

Optimal investment in a defaultable bond

The present paper analyzes the optimal investment strategy in a defaultable (corporate) bond and a money market account in a continuous time model. Due to jumps in the bond price our market model is incomplete. The treatment of information on the firm’s asset value is based on an approach unifying the structural model and the reduced-form model. Specifically, the asset value will be assumed to be observable only at finitely many time points before the maturity of the bond. The optimal investment process will be worked out first for a short time-horizon with a general risk-averse utility function, then a multi-period optimal strategy with logarithmic and power utility will be presented using backward induction. The optimal investment strategy is analyzed numerically for the logarithmic utility.     

Modelling the evolution of credit spreads using the Cox process within the HJM framework: A CDS option pricing model

In this paper a simulation approach for defaultable yield curves is developed within the Heath et al. (1992) framework. The default event is modelled using the Cox process where the stochastic intensity represents the credit spread. The forward credit spread volatility function is affected by the entire credit spread term structure. The paper provides the defaultable bond and credit default swap option price in a probability setting equipped with a subfiltration structure. The Euler–Maruyama stochastic integral approximation and the Monte Carlo method are applied to develop a numerical scheme for pricing. Finally, the antithetic variable technique is used to reduce the variance of credit default swap option prices.     

利用传染模型对含有对手风险的信用证券定价(英文)

本文利用传染模型研究了可违约债券和含有对手风险的信用违约互换的定价。我们在约化模型中引入具有违约相关性的传染模型,该模型假设违约过程的强度依赖于由随机微分方程驱动的随机利率过程和交易对手的违约过程.本文模型可视为Jarrow和Yu(2001)及Hao和Ye(2011)中模型的推广.进一步地,我们利用随机指数的性质导出了可违约债券和含有对手风险的信用违约互换的定价公式并进行了数值分析.     

The Mean-Variance Hedging of a Defaultable Option with Partial Information

Abstract

We consider the mean-variance hedging of a defaultable claim in a general stochastic volatility model. By introducing a new measure Q ⁰, we derive the martingale representation theorem with respect to the investors' filtration . We present an explicit form of the optimal-variance martingale measure by means of a stochastic Riccati equation (SRE). For a general contingent claim, we represent the optimal strategy and the optimal cost of the mean-variance hedging by means of another backward stochastic differential equation (BSDE). For the defaultable option, especially when there exists a random recovery rate we give an explicit form of the solution of the BSDE.     

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In this paper, the insurer is allowed to buy reinsurance and allocate his money among three financial securities: a defaultable corporate zero-coupon bond, a default-free bank account, and a stock, while the instantaneous rate of the stock is described by an Ornstein-Uhlenbeck process. The objective is to maximize the exponential utility of the terminal wealth. We decompose the original optimization problem into two subproblems: a pre-default case and a post-default case. Using dynamic programming principle, and then solving the corresponding HJB equations, we derive the closed-form solutions for the optimal reinsurance and investment strategies and the corresponding value functions