欧式幂期权定价模型中参数及隐含波动率的统计特性

研究了欧式幂期权定价公式中价格的渐近无偏估计和隐含波动率估计的统计特性。利用Chaudhury M.M(1989)提出的研究欧式期极定价公式中渐近无偏估计的方法以及隐含波动率求解方法,研究了两种欧式幂型看涨期权定价公式(欧式看涨期权的价值定义分别为m ax(STα-X,0)和m ax(STα-Xa,0)中的隐含波动率的估计的统计特征、幂函数的幂指数选取以及两种幂函数期权定价公式的优劣。Monte-Carlo统计计算的模拟结果说明。幂期权定价公式中幂指数α取值应为α>0,而且欧式看涨期权的价值定义为m ax(STα-Xα,0)更为合理。     

Simulation methods for valuing Asian option prices in a hyperbolic asset price model

In this paper, we present a Quasi-Monte Carlo approach for pricingEuropean-style Asian options, i.e. for options whose pay-offdepends on the average price of the underlying asset where theaverage is extended over a fixed period up to the maturity date.Following a recent development in mathematical finance, we assumethat the log returns of the asset are not normally but hyperbolicallydistributed. This hypothesis is approved by several authorswith different statistic tests on real financial data. The aimof this paper is to advance the hyperbolic model to the pricingof Asian options, since there only exist pricing formulae forplain vanilla options and some types of exotic options (e.g.power call options, barrier options) so far. We show how onecan obtain prices of general Asian options in such incompletemarkets in an efficient way.     

前向打靶格方法计算变异期权的价格

前向打靶格方法是Banaquand和Latombe在解决非完全型Hamilton—Jacobi—Bellman方程时介绍的．本将用它来解决未定权益定价问题．中首先介绍这种方法。然后用它计算变异期权的价格。     

允许提前违约的信用衍生产品定价模型

本文运用随机过程中的反射原理 ,停时分布以及障碍期权的定价思想扩展了 Merton( 1 975 )提出的信用衍生产品定价模型 ,对允许提前违约且标的资产间具有相关性的信用衍生产品进行定价 ,并给出了该定价模型的解析解     

求解美式回望期权的有限元方法

期权作为一种金融衍生产品,在欧美国家一直很受欢迎.由于其规避风险的特性,期权也吸引了中国投资者的兴趣.基于市场的需求,2015年初,上海证券交易所推出了中国首批期权产品,期权定价问题的研究热潮正席卷全球.本文研究的美式回望期权,是一种路径相关的期权,其支付函数不仅依赖于标的资产的现值,也依赖其历史最值.分析回望期权的特点,不难发现:1)这类期权空间变量的变化范围为二维无界不规则区域,难以应用数值方法直接求解;2)最佳实施边界未知,使得该问题变得高度非线性.本文的主要工作就是解决这两个困难,得到回望期权和最佳实施边界的数值逼近结果.现有的处理问题1)的有效方法是采用标准变量替换、计价单位变换以及Landau变换将定价模型化为一个[0,1]区间上的非线性抛物问题,本文也将沿用这些技巧处理问题1).进一步,采用有限元方法离散简化后的定价模型,并论证了数值解的非负性,提出了利用Newton法求解离散化的非线性系统.最后,通过数值模拟,验证了本文所提算法的高效性和准确性.     

Pricing of long dated equity-linked life insurance contracts

This article adopts an approach to pricing of equity-linked life insurance contracts, which only requires the existence of the numéraire portfolio. An equity-linked life insurance contract is equivalent to a sum of the guaranteed amount and the value of an option on the equity index with some mortality risk attached. The numéraire portfolio equals the growth optimal portfolio and is used as numéraire or benchmark, where the real-world probability measure is taken as pricing measure. To obtain tractable solutions the short rate is modelled as a quadratic form of some Gaussian factor processes. Furthermore, the dynamics of the mortality rate is modelled as a threshold life table. The dynamics of the discounted equity market index or benchmark is modelled by a time transformed squared Bessel process. The equity-linked life insurance contracts are evaluated analytically.     

Explicit representations for the expectations of exponential functionals of the multi-factor variance gamma process and their applications

In this paper we discuss exponential functionals of the multi-factor variance gamma (VG) process. This process is a generalization of the well-known VG process. We obtain analytically the expectations of the considered functionals. Derived formulas are based on values of generalized hypergeometric functions. Applications of the established results to option pricing are given.     

Optimal stopping of switching diffusions with state dependent switching rates

This paper is concerned with a continuous-time and infinite-horizon optimal stopping problem in switching diffusion models. In contrast to the assumption commonly made in the literature that the regime-switching is modeled by an independent Markov chain, we consider in this paper the case of state-dependent regime-switching. The Hamilton–Jacobi–Bellman (HJB) equation associated with the optimal stopping problem is given by a system of coupled variational inequalities. By means of the dynamic programming (DP) principle, we prove that the value function is the unique viscosity solution of the HJB system. As an interesting application in mathematical finance, we examine the problem of pricing perpetual American put options with state-dependent regime-switching. A numerical procedure is developed based on the DP approach and an efficient discrete tree approximation of the continuous asset price process. Numerical results are reported.     

基于不确定理论的风险中性测度及其在欧式期权定价中的应用

首先运用不确定理论推导了相应的不确定风险中性测度,修正了已有文献中涨跌期权不满足无套利原则的问题.然后将所得的风险中性测度用于欧式看涨和看跌期权的定价,并验证了涨跌期权价格之间的平价关系.最后研究了一类利差期权的定价问题,结合定义的风险中性测度给出了期权的定价公式.所推导的不确定风险中性测度与经典的无套利原则相吻合,而且考虑到了问题描述过程中存在的不精确性,弥补了单纯依赖随机理论的不足,可广泛地应用于金融衍生品的定价过程,为投资分析提供一定的理论依据.     

Intensity-based framework for surrender modeling in life insurance

In this paper, we propose an intensity-based framework for surrender modeling. We model the surrender decision under the assumption of stochastic intensity and use, for comparative purposes, the affine models of Vasicek and Cox–Ingersoll–Ross for deriving closed-form solutions of the policyholder’s probability of surrendering the policy. The introduction of a closed-form solution is an innovative aspect of the model we propose. We evaluate the impact of dynamic policyholders’ behavior modeling the dependence between interest rates and surrendering (affine dependence) with the assumption that mortality rates are independent of interest rates and surrendering. Finally, using experience-based decrement tables for both surrendering and mortality, we explain the calibration procedure for deriving our model’s parameters and report numerical results in terms of best estimate of liabilities for life insurance under Solvency II.