改善股本权证定价效果方法的实证研究

本文从模型定价误差形成的原因和用回归方法对我国的股本权证ST长电的定价效果进行检验:提出了消除模型误差的办法;同时也揭示出我国权证市场以及股票市场的一些内在特征及对定价效果的影响.     

关于权证定价修正模型的比较研究——基于交易成本和股息分红因素的分析框架

在我国股权分置改革中，权证推动了证券市场的金融创新。鉴于权证定价可以借鉴期权理论，国外B—S模型对我国权证市场的创新和风险管理具有一定的参考意义。本文采用B—S定价模型定价宝钢认购权证和长电认购权证，分别从交易成本和股息分红的角度进行了相应的模型调整，以改进、完善适应我国权证市场的定价方法。     

我国股本权证定价效果的实证研究

我们应用四种权证定价模型和方法,对我国的股本权证的定价效果进行检验,发现:1)Black-Scholes模型和Monte Carlo方法是比较有效的定价方法;2)有效的程度不很高,存在系统的模型误差;3)模型误差的原因是标的股票收益率分布的非正态性。     

Black-Scholes期权定价、二叉树定价及其在我国权证市场适用性分析

运用B-S期权定价和二叉树定价对我国沪市发行4只认购权证和1只认沽权证的理论价值进行测度,并采用偏离度和T统计量分析两种期权定价方法的定价效率。研究结果表明,与二叉树定价相比,B-S期权定价得到的权证理论价格更加贴近于市场实际价格,其偏离度小于二叉树定价结果的偏离度。由此可见,B-S定价模型更适用于我国权证市场的定价,其定价效率较高。但是,分析的结果也表明,两种定价方法测度的理论价值与实际价格仍存在较大的差异,制度因素可能是导致定价偏差的一个重要原因,因此,如何考虑我国权证市场的实际情况,从而对理论模型进行修正是后续研究的一个重要方向。     

基于遗传算法的BP神经网络在权证定价中的应用

对金融衍生品的定价一直都是理论界和实务界所关注的热点问题之一.传统的参数模型定价方法,容易产生系统性偏差,而神经网络方法在解决这一问题时具有明显的优势.本文基于遗传算法改进的BP神经网络模型(GABP),利用我国8只权证的1050天数据、标的股票1900天的数据和其他所需数据作为训练数据训练网络.研究结果表明,神经网络在权证的定价中效果要优于B-S模型;而RBF模型精度大于BP模型的预测,GABP模型的精度大于RBF模型的预测.     

权证提高了标的股票的定价效率吗——基于我国股票市场实证研究

现阶段在我国,权证提高了标的股票的定价效率了吗?本文围绕这个问题,分析了权证上市后,标的股票的波动性是否减弱、杠杆效应是否消除、长期记忆性是否减轻和系统风险是否降低.通过TARCH模型和带虚拟变量的系统风险分析模型对上述4个方面进行了分析和探讨.不可否认的是.每只标的股票都有一定的特殊性.但是参数估计的结果有助于我们认识权证对标的股票定价效率的影响.而充分认识权证对标的股票的影响有利于股票和其他金融产品定价的合理化.有利于提高金融产品的定价效率,有利于金融创新,有利于我国资本市场的健康发展.基于这些重要的理论和现实意义,本文系统分析了我国的权证对标的股票定价效率的影响,尝试给出分析我国权证影响标的股票定价效率的研究框架和模型.     

基于B-S期权定价公式对权证定价的研究

权证作为一个为规避风险的衍生金融工具.曾经在中国有过一段短暂的权证发展时期.但由于种种原因最终导致权证这种金融衍生工具逐渐淡出市场长达10年之久.2005年8月22日宝钢权证上市,标志着中国证券市场再次推出权证.经过5年多的发展,我国权证市场逐渐向规范和成熟方向努力.本文以长虹CWB1权证为例通过Black-Scholes公式进行定价,并对目前该权证的实际价格情况进行检验,分析其中的原因.     

低波动率溢价条件下的备兑权证定价

作为对传统期权定价模型的改良，本文将不同的波动率模型导入BlackSchole（1973）模型以及Hull＆White（1987）模型，研究了在低波动率溢价条件下各种波动率模型与定价模型结合而形成的新定价模型对中资股背景的备兑权证定价的能力。根据样本所计算的结果显示，Hull＆White模型与GARCH$波动率模型的结合能够较为精准地对备兑权证进行定价。此外，面对我国证券市场可能迎来的备兑权证即将发行的格局，本文还提出了加强发行商资格审批、发行后风险控制监管相对灵活等建议。     

随机参数二叉树期权定价方法及其模拟研究

本文将股票波动性随机变化的因素考虑到二叉树期权定价模型中,得到了可以用数值计算方法实现的一个期权定价方法,该公式比传统二叉树模型更能反映股票波动的异方差性。以五粮液认购权证与五粮液认沽权证为样本,运用马尔科夫链蒙特卡罗方法对其进行了模拟分析,并与B-S模型进行了比较。     

基于分形市场的认股权证定价分析

传统的Black-Scholes期权定价模型没能考虑权证执行的“稀释效应”以及“红利分配”问题，修正的模型虽然解决了这两个问题，但仍然建立在市场有效性的假设基础之上，而分形市场中的分数布朗运动定价模型合理地解决了这些问题。本文以武钢认股权证（WISCO）为例，对认股权证的定价进行了实证探索，并对权证的理论价格与实际价格以及标的证券——武钢股价的走势进行了对比研究，指出了认股权证市场价格的不舍理性和存在的获利机会。     

投资者是非理性的吗——卖空限制下我国权证价格偏离探析

本文研究了影响我国权证价格偏离的主要因素。以往文献的重售动机理论和便利收益理论不能诠释权证定价偏差的不对称性。我们的研究提出理性避险动机是权证价格偏离的主导因素,即我国投资者并不是非理性的进行重售投机,也并没有忽视权证的避险性能。本文避免了以往文献的Black-Scholes模型依赖,在平价准则的基础上构造了非模型的误差度量方法,从而剔除了模型假设导致的价格偏差,保证了研究结果的有效性和准确性。     

Pricing Warrants: An Empirical Study of the Black-Scholes Model and Its Alternatives

This paper uses a sample of over 25,000 daily warrant prices to empirically investigate potential problems with the commonly used warrant pricing model proposed by Black and Scholes as an extension of their call option model. One problem seems to be especially important: the constant variance assumption of the dilution adjusted Black-Scholes model appears to cause biases in model prices for almost all warrants and over the entire sample period. We show that more accurate price forecasts are obtained with a specific form of the constant elasticity of variance model.     

WARRANT PRICING USING OBSERVABLE VARIABLES

The classical warrant pricing formula requires knowledge of the firm value and of the firm‐value process variance. When warrants are outstanding, the firm value itself is a function of the warrant price. Firm value and firm‐value variance are then unobservable variables. I develop an algorithm for pricing warrants using stock prices, an observable variable, and stock return variance. The method also enables estimation of firm‐value variance. A proof of existence of the solution is provided.     

In-the-Money Warrant Extensions

This paper examines the warrant price and stock price reactions to the extension of the expiration date of in-the-money warrants. The warrant prices increase significantly in response to the announcement, consistent with option pricing theory. Shareholders experience no significant abnormal returns at the announcement, contrary to the conjecture that an extension will transfer wealth from shareholders. There is support for the idea that firms extend warrant life because the existing assets' cash flow obviates the need for additional financing. The data show that both the stocks and the warrants perform poorly in the month following the extension announcement.     

Warrant pricing: a review of empirical research

Recently, several warrant pricing studies have become available for different models as well as for different countries. The most important conclusions that can be drawn from reviewing these studies are: (1) it is not necessary to make a correction on option valuation models for the dilution effect; (2) the only model that systematically outperforms the Black-Scholes (1973) type models is the Square Root model; (3) US and German warrants seem to be priced correctly, while deviations are found for English and Japanese warrants (underpriced by the market) and Swiss and Dutch warrants (overpriced by the market).     

The Listing, Size, and Value of Equity Warrants

This note examines whether listing on a major exchange raises the value of warrants. Such an increase is plausible, given the generally small size of warrant issues and the enhanced liquidity that organized trading can provide. Using Black-Scholes pricing techniques, the study concludes that listing has a positive and substantial impact on the per unit price of seasoned warrant issues. Moreover, the tests indicate that the impact is so consistently large for small warrant issues that firms should consider listing these securities at the time of issuance.     

沪深权证价格偏离分析

沪深证券市场权证理论价格与权证市场价格的偏离现象主要不是理论定价公式的输入变量误差导致的,而是因为股票收益率与权证收益率之间的相关系数与理论预期不一致,乃至相冲突所导致的。权证理论价格与市场价格偏离的主要原因是在当前的交易制度安排下,由于市场限制(摩擦)抑制了套利交易,导致权证市场投机交易占主导,以致权证市场价格偏离长期均衡水平。     

Some Hypotheses on the Valuation of Stock Warrants

Stock warrants are often portrayed as securities that yield supernormal returns while their counterpart stocks only earn moderate yields. Those returns seem inconsistent with efficient capital markets. A present-value warrant model is developed in this paper. This model assumes that warrants grow at a rate appropriate to their risk class. The model suggests that warrant values vary directly with growth of the stock and the time remaining to exercise, and vary inversely with the warrant holder's cost of capital.     

The risk-shifting effect and the value of a warrant

The exercise of a warrant leads to the well-known dilution phenomenon, the effects of which have been extensively studied over the last four decades. In contrast, the existing literature has paid inadequate attention to the volatility spillover between stockholders and warrant holders. This ‘risk-shifting effect’ has significant implications for warrant pricing, since any formula that assumes a constant volatility of stock returns produces a bias. In this paper we show that a CEV process with a specific elasticity parameter properly models the stochastic volatility of stock returns for a firm with warrants outstanding. In addition, we propose an approximate analytical formula, exclusively based on observable market variables, that is able to absorb the risk-shifting bias.