Explicit solution of an infinite horizon optimal stopping problem for a Levy processes with a polynomial reward function is given, in terms of the overall supremum of the process, when the solution of the problem is one-sided. The results are obtained via the generalization of known results about the averaging function associated with the problem. This averaging function can be directly computed in case of polynomial rewards. To illustrate this result, examples for general quadratic and cubic polynomials are discussed in case the process is Brownian motion, and the optimal stopping problem for a quartic polynomial and a Kou's process is solved.
Predicting the last zero of a spectrally negative Lévy process
最后通过时间出现在应用概率的许多领域,包括风险理论和退化模型。这样的时间显然不是停时,因为它们依赖于底层过程的整个路径。我们考虑的问题,找到一个停时,最小化的$L^1$ -距离的最后一次谱负Lévy过程$X$是在零以下。对于具有连续路径的过程,有限时域设置中的相关问题的例子是Du Toit et al.(2008)和Glover and Hulley(2014),其中最后一个零点分别针对具有漂移的布朗运动和瞬态扩散进行预测。当我们考虑无限视界设置时,只有当Lévy过程漂移到$\infty$时,这个问题才是有趣的,我们将在整个过程中假设这一点。现有的结果使我们能够重写的问题作为一个经典的最优停止问题,即适应的支付过程。我们使用一个直接法来显示,最佳的停时是由第一次通过时间以上的水平定义的中位数的卷积与本身的分布函数的$-\inf_{t\geq 0}X_t$。我们也会在连续和/或平滑拟合保持时进行验证。
We consider the optimal prediction problem of stopping a spectrally negative Lévy process as close as possible to a given distance $b \geq 0$ from its ultimate supremum, under a squared error penalty function. Under some mild conditions, the solution is fully and explicitly characterised in terms of scale functions. We find that the solution has an interesting non-trivial structure: if $b$ is larger than a certain threshold then it is optimal to stop as soon as the difference between the running supremum and the position of the process exceeds a certain level (less than $b$), while if $b$ is s…
Previous authors have considered optimal stopping problems driven by the running maximum of a spectrally negative Lévy process $X$, as well as of a one-dimensional diffusion. Many of the aforementioned results are either implicitly or explicitly dependent on Peskir's maximality principle. In this article, we are interested in understanding how some of the main ideas from these previous works can be brought into the setting of problems driven by the maximum of a class of Markov additive processes (more precisely Markov modulated Lévy processes). Similarly to previous works in the Lévy setting, …
Optimal Stopping for Strong Markov Processes: Explicit solutions and verification theorems for diffusions, multidimensional diffusions, and jump-processes
We provide general conditions ensuring that the value functions of some nonlinear stopping problems with finite horizon converge to the value functions of the corresponding problems with infinite horizon. Our result can be formulated as result on stability, with respect to time horizon, of nonlinear $f$-expectations. We also study the rate of convergence. Many examples are given to illustrate our results. They include the analysis of time asymptotics of the fair prices of American options in a multidimensional exponential Lévy model.
Given a spectrally negative Lévy process, we predict, in a $L_1$ sense, the last passage time of the process below zero before an independent exponential time. This optimal prediction problem generalises Baurdoux and Pedraza (2020) where the infinite horizon problem is solved. Using a similar argument as that in Urusov (2005), we show that this optimal prediction problem is equivalent to solving an optimal prediction problem in a finite horizon setting. Surprisingly (unlike the infinite horizon problem) an optimal stopping time is based on a curve that is killed at the moment the mean of the e…
We introduce a new formulation of reflected BSDEs and doubly reflected BSDEs associated with irregular obstacles. In the first part of the paper, we consider an extension of the classical optimal stopping problem over a larger set of stopping systems than the set of stopping times (namely, the set of split stopping times), where the payoff process $ξ$ is irregular and in the case of a general filtration. Split stopping times are a powerful tool for modeling financial contracts and derivatives that depend on multiple conditions or triggers, and for incorporating stochastic processes with jumps …
Optimal stopping problems for the maximum process with upper and lower caps
研究了由谱负Lévy过程$X$的运行极大值驱动的最优停止问题.更确切地说,我们感兴趣的修改Shepp-Shiryaev最优停止问题[阿夫拉姆,Kyprianou和皮斯托瑞斯安。14(2004)215-238; Shepp和Shiryaev Ann. Appl. Probab. 3(1993)631-640; Shepp和Shiryaev Theory Probab. 39(1993)103-119]。首先,我们考虑一个上限版本的Shepp-Shiryaev最优停止问题,并提供解决方案明确的尺度函数。特别是,最佳停止边界的特点是由一个常微分方程,涉及尺度函数和变化,根据路径变化的$X$。其次,在[Shepp,Shiryaev和Sulem Advances in Finance and Stochastics(2002)271-284 Springer]的精神下,我们考虑了Shepp-Shiryaev最优停止问题的上限版本的修改,在这个意义上,停止的决定必须在过程$X$下降到给定水平以下之前做出。
The Gapeev-Kühn stochastic game driven by a spectrally positive Lévy process
Gapeev and Kühn(2005)研究了在布朗运动和带指数跳的复合泊松过程驱动下,永续可转换债券的随机对策。我们考虑相同的随机对策,但由一个谱正Lévy过程驱动。我们建立了一个完整的解决方案,游戏指示四个主要参数制度,以及表征连续和光滑的配合发生。在Gapeev和Kühn(2005)中,证明方法主要基于解决一个自由边界值问题。在本文中,我们使用波动理论和辅助最优停止问题来找到一个解决方案的游戏。