Margining Option Portfolios by Network Flows

As shown in [Rudd and Schroeder, 1982], the problem of margining option portfolios where option spreads with two legs are used for offsetting can be solved in polynomial time by network flow algorithms. However, spreads with only two legs do not provide sufficient accuracy in measuring risk. Therefore, margining practice also employs spreads with three and four legs. A polynomial time solution to the extension of the problem where option spreads with three and four legs are also used for offsetting is not known. In this paper we propose a heuristic network flow algorithm for this extension and present a computational study that proves high efficiency of this algorithm in margining practice

Portfolio Margining: Strategy vs Risk

This paper presents the results of a novel mathematical and experimental analysis of two approaches to margining customer accounts, strategy-based and risk-based. Building combinatorial models of hedging mechanisms of these approaches, we show that the strategy-based approach is, at this point, the most appropriate one for margining security portfolios in customer margin accounts, while the risk-based approach can work efficiently for margining only index portfolios in customer mar-gin accounts and inventory portfolios of brokers. We also show that the application of the risk-based approach to security portfolios in customer margin accounts is very risky and can result in the pyramid of debt in the bullish market and the pyramid of loss in the bearish market. The results of this paper support the thesis that the use of the risk-based approach to margining customer accounts with positions in stocks and stock options since April 2007 influenced and triggered the U.S. stock market crash in October 2008. We also provide recommendations on ways to set appropriate margin requirements to help avoid such failures in the future

Combinatorics of Option Spreads: The Margining Aspect

In December 2005, the U.S. Securities and Exchange Commission approved margin rules for complex option spreads with 5, 6, 7, 8, 9, 10 and 12 legs. Only option spreads with 2, 3 or 4 legs were recognized before. Taking advantage of option spreads with a large number of legs substantially reduces margin requirements and, at the same time, adequately estimates risk for margin accounts with positions in options. In this paper we present combinatorial models for known and newly discovered option spreads with up to 134 legs. We propose their full characterization in terms of matchings, alternating cycles and chains in graphs with bicolored edges. We show that the combinatorial analysis of option spreads reveals powerful hedging mechanisms in the structure of margin accounts, and that the problem of minimizing the margin requirement for a portfolio of option spreads can be solved in polynomial time using network flow algorithms. We also give recommendations on how to create more efficient margin rules for options

Structural pricing of XVA metrics for energy commodities OTC trades

The aim of the present Chapter is to improve of the structural rst-passage framework built in Chapter 1 along several directions as well as test its robustness. Since typically commodity trades are not clearable under Central Clearing Counterparts (CCPs), it is worthy to assess the eect of bilateral Collateral Support Annex (CSA) agreements on CVA/DVA metrics. Moreover I introduce within my CCR modelling, the impact of state-dependent stochastic recovery rates. Furthermore, in order to stress-test my framework, I investigate the eects on CCR measures of multiplicative shocks to the two major drivers in the game: credit and volatility. Finally I propose an alternative balance-sheet calibration based on hybrid market/accounting data which is well suited in the commodity context in the light of small and medium size of corporations usually operating in the EU commodity derivatives market for risk-management purposes.The global nancial crisis revealed that no economic entity can be considered default-free any more. Because of that, both banks and corporations have to deal with bilateral Counterparty Credit Risk (CCR) in their OTC derivatives trades. Such evidence implies the fair pricing of these risks, namely the Credit Valuation Adjustment (CVA) and its counterpart, the Debt Valuation Adjustment (DVA). Despite the more commonly used reduced-form approach, in this work the random default time is addressed via a structural approach a la Black and Cox (1976), so that the bankruptcy of a given rm is modelled as the rst-passage time of its equity value from a predetermined lower barrier. As in Ballotta et al. (2015), I make use of a time-changed Levy process as underlying source of both market and credit risk. The main advantage of this setup relies on its superior capability to replicate non null short-term default probabilities, unlike pure diusion models. Moreover, a numerical computation of the valuation adjustments for bilateral CCR in the context of energy commodities OTC derivatives contracts has been performed.The global nancial crisis revealed that no economic entity can be considered default-free any more, so that both banks and corporate rms have to cope with bilateral Counterparty Credit Risk (CCR) when negotiating OTC derivatives. Since the mainstream approach typically used in practical settings is to evaluate derivatives in terms of the cost of their respective hedging strategies, the pricing of CCR metrics implicitly relates to the way these strategies are nanced. Within the numerical section of the present work, the valuation adjustments for CCR have been computed. Moreover, the role played by funding costs and their impact in widening bid-ask spreads have been assessed. A similar reasoning has been applied for the investigation of the cost of funding Initial Margins (IM), typically eective on top of Variation Margins (VM) when trading under Central Clearing Counterparties (CCPs). As the Initial Margin Valuation Adjustment (MVA) is concerned, it is here showed that, dierently from what can happen for FVAs, no osetting eect can materialize. As a consequence, in aggregate terms IMs can cause systemic liquidity eects. The computed XVA metrics are relative to energy commodities OTC derivative trades

Credit derivatives, macro risks, and systemic risks

This paper explores some bigger-picture risks associated with credit derivatives. Drawing a distinction between the market's perception of credit and "real credit" as reflected in the formal definition of a credit event, the author examines the well-documented macro drivers of credit generally. ; The author next enumerates frequently cited concerns with credit derivatives: the exceedingly large notional trade in credit default swaps relative to outstanding debt, the increasing involvement of hedge funds in these products, and operational concerns that have surfaced in the past year or two. ; The paper then considers the possibilities of associated systemic risk, looking at the issues of modeling and proper hedging, risk management, and valuation of new and sometimes complex credit derivative instruments. ; Despite the inherent risks involved in credit derivatives, the market for these instruments continues to grow rapidly as people find them practical and beneficial for hedging risk, generating income, and distributing credit risk among a broader institutional base. Evolving market practices and safeguards should help establish a more efficient, transparent marketplace. Whether credit risk is best allocated outside of the traditional financial intermediaries remains an open question.Credit derivatives ; Risk

Central clearing configurations : implications for South African derivative markets

After the financial crisis of 2008-2009, central counterparties (CCPs) emerged as an important mechanism to mitigate against counterparty credit risk and stem the spread of contagion in a time of crisis. Trading in derivative instruments, especially opaque, illiquid and complex in-struments, were seen as the cause of much of the quagmire in which the global economy found itself. At the Pittsburgh summit in 2009, the Group of 20 Nations (G20) made some fundamental commitments on the reform of international derivatives markets. One of the main commitments was to have standardised OTC derivatives cleared through central coun-terparties by the year 2020. In South Africa, the only CCP is the clearing house for exchange traded derivatives operated by the Johannesburg Stock Exchange (JSE); five major South Af-rican banks are direct clearing members of JSE Clear. Most of the standardised OTC deriva-tive transactions are interest rate, and to a much lesser degree forex, in nature. The London Clearing House (LCH) clears the vast majority of centrally cleared ZAR interest rate swaps. All South African banks clear most of their trades executed with foreign counterparts at LCH but only one has a subsidiary that is a direct clearing member of LCH. There is a large amount of ZAR interest rate swap activity in SA which is not centrally cleared. This study examines the efficiency and dynamics of central clearing in this setting. It further notes the recent de-velopments in the current central clearing landscape and compares aspects thereof in South Africa to international CCPs. The framework developed by Duffie & Zhu (2011) is then used to examine efficiencies of different configurations of central clearing of derivatives in the South African context.Dissertation (MSc (Financial Engineering))--University of Pretoria, 2021.Mathematics and Applied MathematicsMSc (Financial Engineering)Unrestricte

Derivatives Clearing and Brexit: A comment on the proposed EMIR revisions. ECMI Policy Brief No. 25 / November 2017

No less than three substantive pieces of EU legislation have been proposed over the eightmonth period from November 2016 to June 2017, modifying or complementing the original EMIR Regulation of 2012. This contribution analyses the changes that have taken place in EU OTC derivatives markets since the new rules were adopted, and discusses the three drafts. It argues that the European Commission should have assessed risk management with CCPs in more detail and should have proposed a more integrated architecture for the supervision and resolution of CCPs. It further argues that the three proposals should have been part of one single package to facilitate the legislative process of such technical measures

Hedging Volumetric Risks of Solar Power Producers Using Weather Derivative Smart Contracts on a Blockchain Marketplace

The vulnerability of solar power producers to sunshine fluctuations exposes them to the volumetric risk that future electricity generation may deviate from predicted generation. Weather derivatives have recently emerged as a tool for hedging the volumetric risks of these power producers. However, the state-of-the-art instruments have several shortcomings, contributing to their limited application in the industry. Therefore, novel solar radiation-based weather derivative smart contract arrangements on a blockchain marketplace are proposed to address some of the main limitations of traditional instruments. In this regard, the cash flow of solar generators is modelled to assess the weather elements causing its stochasticity. Using this information, novel smart contract arrangements on a blockchain marketplace with solar radiation days as the underlying weather index are developed and analytically valued. Thereafter, a suite of novel smart contract autonomous mechanisms compelling contracting parties to behave rationally and maintain an enduring arrangement is presented. Finally, a trading strategy based on the developed smart contract arrangements is proposed to minimize the power producers’ volatility risk. Results emanating from notional simulations indicate that the proposed approach could be more suitable for hedging the volumetric risks of solar power producers than traditional instruments.Sustainable Energy Authority of Ireland (SEAI