The <Emphasis Type="Italic">β</Emphasis>-variance gamma model

Kuznetsov (Ann Appl Prob, 2009) introduces a 10-parameter family of Lévy processes for which the Wiener-Hopf factors and the distribution of the running supremum (infimum) can be determined semi-analytically. In this text we will examine the numerical performance of this so-called β-family, both in the equity world and in the field of credit risk. In order to do this, we will calibrate a particular member of this family to a vanilla option surface (by means of the Fast Fourier Transform-technique due to Carr and Madan (J Comput Fin 2(4):61–73, 1999) and use the resulting parameters to determine the prices of a digital down-and-out barrier (DDOB) option, written on the same underlying. In a second experiment, we will try and calibrate the model to some real-life credit default swap (CDS) term structures. The parameters of the model under investigation are chosen such that its Lévy density is approximately equal to that of the famous Variance Gamma (VG) process, which will serve as a benchmark. Hence, the former will be referred to as the β-VG model. The option prices will be determined both semi-analytically [using the formulas derived by Kuznetsov (Ann Appl Prob, 2009)] and through a Monte-Carlo simulation. However, the CDS spreads will only be determined semi-analytically, due to the very close relation between pricing DDOB options and determining the par spread of a CDS. Furthermore, in both cases, the results will be compared with the ones obtained using the VG model [Cf. Schoutens (Lévy processes in finance: pricing financial derivatives, Wiley , Chichester, 2003) and, Cariboni and Schoutens (Levy processes in credit risk, Wiley, Chichester, 2009)]. It will turn out that, w.r.t. vanilla option prices, the β-VG model performs almost identically as the VG model, whereas the semi-analytical expressions by Kuznetsov (Ann Appl Prob, 2009) lead to a (fast and) accurate pricing of DDOB options and CDSs.     

Inside the <Emphasis FontCategory="SansSerif">“</Emphasis>black box<Emphasis FontCategory="SansSerif">”</Emphasis> of private in-house meetings

We examine information content and related insider trading around private in-house meetings between corporate insiders and investors and analysts. We use a hand-collected dataset of approximately 17,000 private meeting summary reports of Shenzhen Stock Exchange firms over 2012–2014. We find that these private meetings are informative and corporate insiders conducted over one-half of their stock sales (totaling $8.7 billion) around these meetings. Some insiders time their transactions and earn substantial gains by selling (purchasing) relatively more shares before bad (good) news disclosures while postponing selling (purchasing) when good (bad) news is to be disclosed in the meeting. Finally, we conduct a content analysis of published meeting summary reports and find that the tone in these reports is associated with stock market reactions around (1) private meetings themselves, (2) subsequent public release of private meeting details, (3) subsequent earnings announcements and (4) future stock performance.     

Esscher transforms and the minimal entropy martingale measure for exponential Lévy models

In this paper we offer a systematic survey and comparison of the Esscher martingale transform for linear processes, the Esscher martingale transform for exponential processes, and the minimal entropy martingale measure for exponential Lévy models, and present some new results in order to give a complete characterization of those classes of measures. We illustrate the results with several concrete examples in detail.     

Do equity-based <Emphasis Type="Italic">Sukuk</Emphasis> structures in Islamic capital markets manifest the objectives of Shariah??

The Islamic capital market is an important component of the overall Islamic financial system especially in providing an element of liquidity to the otherwise illiquid assets. Like its conventional counterpart, Islamic capital markets complement the investment role of the Islamic banking sector in raising funds for long-term investment. These long-term investments are facilitated through various Shariah contracts and instruments ensuring efficient mobilisation of resources and their optimal allocation. This article aims at reviewing equity-based Sukuk structure, which is one of the most popular instruments used in Islamic capital market today. This article argues that some innovations made in structuring Sukuk, which try to achieve the same economic outcome like conventional instruments, distort the vision of Islamic economics based on justice and equitability. These visions are deeply inscribed in the objectives of Shariah, also known as Maqasid al-Shariah. This distortion stems from the restricted view of understanding Shariah, by only focussing on the legal forms of a contract rather than the substance especially when structuring a financial product. The overemphasis on form over substance leads to potential abuse of Shariah principles in justifying certain contracts, which in fact are contradictory to the Shariah text and ultimately undermining the higher objectives of Shariah. In the final analysis, this article concludes that the substance of a contract that has greater implications to the realisation of Maqasid al-Shariah should be equally looked into. Otherwise, Islamic finance just appears as an exercise of semantics; the functions and operations are really no different from conventional banks, except in the use of euphemisms to disguise interest and circumvent the many Shariah prohibitions.     

Pricing bounds and approximations for discrete arithmetic Asian options under time-changed Lévy processes

We derive efficient and accurate analytical pricing bounds and approximations for discrete arithmetic Asian options under time-changed Lévy processes. By extending the conditioning variable approach, we derive the lower bound on the Asian option price and construct an upper bound based on the sharp lower bound. We also consider the general partially exact and bounded (PEB) approximations, which include the sharp lower bound and partially conditional moment matching approximation as special cases. The PEB approximations are known to lie between a sharp lower bound and an upper bound. Our numerical tests show that the PEB approximations to discrete arithmetic Asian option prices can produce highly accurate approximations when compared to other approximation methods. Our proposed approximation methods can be readily applied to pricing Asian options under most common types of underlying asset price processes, like the Heston stochastic volatility model nested in the class of time-changed Lévy processes with the leverage effect.     

COS method for option pricing under a regime-switching model with time-changed Lévy processes

We extend the regime-switching model to the rich class of time-changed Lévy processes and use the Fourier cosine expansion (COS) method to price several options under the resulting models. The extension of the COS method to price under the regime-switching model is not straightforward because it requires the evaluation of the characteristic function which is based on a matrix exponentiation which is not an easy task. For a two-state economy, we give an analytical expression for computing this matrix exponential, and for more than two states, we use the Carathéodory–Fejér approximation to find the option prices efficiently. In the new framework developed here, it is possible to allow switches not only in the model parameters as is commonly done in literature, but we can also completely switch among various popular financial models under different regimes without any additional computational cost. Calibration of the different regime-switching models with real market data shows that the best models are the regime-switching time-changed Lévy models. As expected by the error analysis, the COS method converges exponentially and thus outperforms all other numerical methods that have been proposed so far.     

Banking Products: You <Emphasis Type="Italic">Can</Emphasis> Take Them with You,So Why Don’t You?

Policymakers around the world call for more competition in the banking sector. One prerequisite to achieving this is customer mobility. Despite its policy relevance, surprisingly little is known about consumers’ bank switching behaviour. We show that the principal reasons to stay at one’s bank are a good bank-customer relationship, practical barriers, and the perception that there is not much benefit in switching. Moreover, we find that the reported propensity to switch varies across banking products. For the main current and savings accounts, this propensity is most strongly related to the bank-customer relationship, while for mortgage loans it is especially linked to switching experience. These findings have important implications for antitrust policy; they provide an argument against using a cluster-based legal standard for the analysis of competition and in favour of a disaggregated approach. Regarding the effectiveness of hypothetical policy initiatives to lower switching barriers, we find that the reported switching propensity with current accounts is higher in the case of account number portability, while more knowledge of the existing switching service has no significant effect. Lastly, scenario analysis shows that a policy of allowing new foreign banks to enter the savings market is less promising for enhancing mobility than a policy that increases the number of domestic players.     

The critical price for the American put in an exponential Lévy model

This paper considers the behavior of the critical price for the American put in the exponential Lévy model when the underlying stock pays dividends at a continuous rate. We prove the continuity of the free boundary and give a characterization of the critical price at maturity, generalizing a recent result of S.Z. Levendorskiǐ (Int. J. Theor. Appl. Finance 7:303–336, 2004).      

Die Auswirkungen der Finanzkrise sowie von Solvency II auf <Emphasis Type=Italic>Insurance-linked Securities</Emphasis>

Der Beitrag stellt Insurance-linked Securities (“ILS”) als Instrument des alternativen Risikotransfers dar und grenzt ILS von anderen Instrumenten des alternativen Risikotransfers ab.     

<Emphasis Type="Italic">K</Emphasis>-fold cross validation performance comparisons of six naive portfolio selection rules: how naive can you be and still have successful out-of-sample portfolio performance?

Recent research reports that optimal portfolio selection models often perform worse than equal-weight naive diversification in out-of-sample testing. This paper extends this line of inquiry by comparing the out-of-sample performance of the equal-weight naive strategy to the out-of-sample performance of five alternative naive strategies, each of which derives from a simple heuristic that does not require any optimization. Out-of-sample portfolio performance is assessed by mean, standard deviation, skewness, and Sharpe ratio; k-fold cross validation is used as the out-of-sample testing mechanism. The results indicate that the proposed naive heuristic rules exhibit strong out-of-sample performance, in most cases superior to the equal-weight naive strategy. These findings are consequential for at least two reasons: first, if these simple heuristic-based rules outperform the equal-weight naive strategy, then by transitivity they can outperform the mean–variance- and shortfall-optimal portfolio rules that have been shown in the literature to be inferior to the equal-weight naive rule, which further emphasizes the out-of-sample fragility of “optimal” methods; and second, among naive diversification strategies, some appear more robust in out-of-sample testing than others, hence the proposed methods may be useful when forming mixed portfolio selection models wherein a naive strategy is combined with an optimal strategy to improve performance.