Portfolio Optimization: Thinking Outside the Style Box
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Managing Volatility Risk
Managing Volatility Risk Innovation of Financial Derivatives, Stochastic Models and Their Analytical Implementation Chenxu Li Submitted in partial fulfillment of the Requirements for the degree of Doctor of Philosophy in the Graduate School of Arts and Sciences COLUMBIA UNIVERSITY 2010 c 2010 Chenxu Li All Rights Reserved ABSTRACT Managing Volatility Risk Innovation of Financial Derivatives, Stochastic Models and Their Analytical Implementation Chenxu Li This dissertation investigates two timely topics in mathematical finance. In partic- ular, we study the valuation, hedging and implementation of actively traded volatil- ity derivatives including the recently introduced timer option and the CBOE (the Chicago Board Options Exchange) option on VIX (the Chicago Board Options Ex- change volatility index). In the first part of this dissertation, we investigate the pric- ing, hedging and implementation of timer options under Heston’s (1993) stochastic volatility model. The valuation problem is formulated as a first-passage-time problem through a no-arbitrage argument. By employing stochastic analysis and various ana- lytical tools, such as partial differential equation, Laplace and Fourier transforms, we derive a Black-Scholes-Merton type formula for pricing timer options. This work mo- tivates some theoretical study of Bessel processes and Feller diffusions as well as their numerical implementation. In the second part, we analyze the valuation of options on VIX under Gatheral’s double mean-reverting stochastic volatility model, which is able to consistently price options on S&P 500 (the Standard and Poor’s 500 index), VIX and realized variance (also well known as historical variance calculated by the variance of the asset’s daily return). -
Hedging Volatility Risk
Journal of Banking & Finance 30 (2006) 811–821 www.elsevier.com/locate/jbf Hedging volatility risk Menachem Brenner a,*, Ernest Y. Ou b, Jin E. Zhang c a Stern School of Business, New York University, New York, NY 10012, USA b Archeus Capital Management, New York, NY 10017, USA c School of Business and School of Economics and Finance, The University of Hong Kong, Pokfulam Road, Hong Kong Received 11 April 2005; accepted 5 July 2005 Available online 9 December 2005 Abstract Volatility risk plays an important role in the management of portfolios of derivative assets as well as portfolios of basic assets. This risk is currently managed by volatility ‘‘swaps’’ or futures. How- ever, this risk could be managed more efficiently using options on volatility that were proposed in the past but were never introduced mainly due to the lack of a cost efficient tradable underlying asset. The objective of this paper is to introduce a new volatility instrument, an option on a straddle, which can be used to hedge volatility risk. The design and valuation of such an instrument are the basic ingredients of a successful financial product. In order to value these options, we combine the approaches of compound options and stochastic volatility. Our numerical results show that the straddle option is a powerful instrument to hedge volatility risk. An additional benefit of such an innovation is that it will provide a direct estimate of the market price for volatility risk. Ó 2005 Elsevier B.V. All rights reserved. JEL classification: G12; G13 Keywords: Volatility options; Compound options; Stochastic volatility; Risk management; Volatility index * Corresponding author. -
Portfolio Optimization and Long-Term Dependence1
Portfolio optimization and long-term dependence1 Carlos León2 and Alejandro Reveiz3 Introduction It is a widespread practice to use daily or monthly data to design portfolios with investment horizons equal or greater than a year. The computation of the annualized mean return is carried out via traditional interest rate compounding – an assumption free procedure –, while scaling volatility is commonly fulfilled by relying on the serial independence of returns’ assumption, which results in the celebrated square-root-of-time rule. While it is a well-recognized fact that the serial independence assumption for asset returns is unrealistic at best, the convenience and robustness of the computation of the annual volatility for portfolio optimization based on the square-root-of-time rule remains largely uncontested. As expected, the greater the departure from the serial independence assumption, the larger the error resulting from this volatility scaling procedure. Based on a global set of risk factors, we compare a standard mean-variance portfolio optimization (eg square-root-of-time rule reliant) with an enhanced mean-variance method for avoiding the serial independence assumption. Differences between the resulting efficient frontiers are remarkable, and seem to increase as the investment horizon widens (Figure 1). Figure 1 Efficient frontiers for the standard and enhanced methods 1-year 10-year Source: authors’ calculations. 1 We are grateful to Marco Ruíz, Jack Bohn and Daniel Vela, who provided valuable comments and suggestions. Research assistance, comments and suggestions from Karen Leiton and Francisco Vivas are acknowledged and appreciated. As usual, the opinions and statements are the sole responsibility of the authors. -
The Cross-Section of Volatility and Expected Returns
THE JOURNAL OF FINANCE • VOL. LXI, NO. 1 • FEBRUARY 2006 The Cross-Section of Volatility and Expected Returns ANDREW ANG, ROBERT J. HODRICK, YUHANG XING, and XIAOYAN ZHANG∗ ABSTRACT We examine the pricing of aggregate volatility risk in the cross-section of stock returns. Consistent with theory, we find that stocks with high sensitivities to innovations in aggregate volatility have low average returns. Stocks with high idiosyncratic volatility relative to the Fama and French (1993, Journal of Financial Economics 25, 2349) model have abysmally low average returns. This phenomenon cannot be explained by exposure to aggregate volatility risk. Size, book-to-market, momentum, and liquidity effects cannot account for either the low average returns earned by stocks with high exposure to systematic volatility risk or for the low average returns of stocks with high idiosyncratic volatility. IT IS WELL KNOWN THAT THE VOLATILITY OF STOCK RETURNS varies over time. While con- siderable research has examined the time-series relation between the volatility of the market and the expected return on the market (see, among others, Camp- bell and Hentschel (1992) and Glosten, Jagannathan, and Runkle (1993)), the question of how aggregate volatility affects the cross-section of expected stock returns has received less attention. Time-varying market volatility induces changes in the investment opportunity set by changing the expectation of fu- ture market returns, or by changing the risk-return trade-off. If the volatility of the market return is a systematic risk factor, the arbitrage pricing theory or a factor model predicts that aggregate volatility should also be priced in the cross-section of stocks. -
Do Equity Prices Reflect the Ultra-Low Interest Rate Environment?
27 FEBRUARY 2020 — N O . 1 Do equity prices reflect the ultra-low interest rate environment? Søren Lejsgaard Autrup Jonas Ladegaard Hensch The viewpoints and conclusions stated are the responsibility Principal Economist Economist of the individual contributors, and do not necessarily reflect ECONOMICS AND ECONOMICS AND the views of Danmarks Nationalbank. MONETARY POLICY MONETARY POLICY [email protected] [email protected] ECONOMIC MEMO — DANMARKS NATIONALBANK 27 FEBRUARY 2020 — N O . 1 Do equity prices reflect the ultra-low interest rate environment? The equity risk premium has Investors face a choice when deciding where to about doubled after the financial invest today: Get a certain return on bonds crisis, amid a sharp decline in offering very low or negative returns, or buy a interest rates and an unchanged risky equity and expect to get around 7 per cent per annum, but with downside and upside required return on equities. risks. Before the financial crisis of 2007-08, the trade-off looked different: The expected return The increase in the premium on equities was at the same level, but the entailed a lower pass-through of alternative looked much more favorable with monetary policy rates to the total bond yields around 4 per cent. In other words, financing costs of corporations. the equity risk premium, defined as the That may help to explain why additional return required as compensation for corporate investments have not investing in equities rather than risk-free assets rebounded faster and stronger (bonds), has about doubled to around 7 per after the financial crisis. cent. Still, bonds are in high demand and no major, global rotation between asset classes has taken place so far. -
Risk Management of Investments in Structured Credit Products
Risk Management of Investments in Structured Credit Products Background A growing number of FDIC-supervised institutions are experiencing deterioration in financial performance as a result of investments in structured credit products.1 The underlying collateral of certain structured credit products has performed poorly. As a result, the level of credit support for senior tranches has diminished, the volume and severity of credit rating downgrades have increased, liquidity has declined, prices are not transparent, and price volatility has increased. Consequently, an increasing number of financial institutions are recognizing other-than-temporary impairment (OTTI) charges and substantial fair value markdowns. Some institutions have invested in structured products in volumes representing concentrations of capital. In some cases, significant purchases were initiated after the credit market turmoil began and, in some cases, funding came from brokered deposits or other volatile funding sources. The FDIC is concerned that financial institutions are not appropriately identifying and controlling the risks inherent in complex structured credit products. Examiners are identifying weaknesses in management’s understanding of product risks, due diligence efforts, portfolio diversification standards, and application of proper accounting standards. Purpose This letter clarifies the application of existing supervisory guidance to structured credit products. Guidance referenced comes primarily from the 1998 “Supervisory Policy Statement on Investment Securities and End-User Derivatives Activities” (Policy Statement), and the “Uniform Agreement on the Classification of Assets and Appraisal of Securities” (Uniform Agreement).2 Topics addressed in this letter include investment suitability and due diligence, the use of external credit ratings, pricing and liquidity, and adverse classification of investment securities. FDIC-supervised institutions should revisit outstanding guidance and incorporate this document’s clarifications into existing policies and processes. -
A Multi-Objective Approach to Portfolio Optimization
Rose-Hulman Undergraduate Mathematics Journal Volume 8 Issue 1 Article 12 A Multi-Objective Approach to Portfolio Optimization Yaoyao Clare Duan Boston College, [email protected] Follow this and additional works at: https://scholar.rose-hulman.edu/rhumj Recommended Citation Duan, Yaoyao Clare (2007) "A Multi-Objective Approach to Portfolio Optimization," Rose-Hulman Undergraduate Mathematics Journal: Vol. 8 : Iss. 1 , Article 12. Available at: https://scholar.rose-hulman.edu/rhumj/vol8/iss1/12 A Multi-objective Approach to Portfolio Optimization Yaoyao Clare Duan, Boston College, Chestnut Hill, MA Abstract: Optimization models play a critical role in determining portfolio strategies for investors. The traditional mean variance optimization approach has only one objective, which fails to meet the demand of investors who have multiple investment objectives. This paper presents a multi- objective approach to portfolio optimization problems. The proposed optimization model simultaneously optimizes portfolio risk and returns for investors and integrates various portfolio optimization models. Optimal portfolio strategy is produced for investors of various risk tolerance. Detailed analysis based on convex optimization and application of the model are provided and compared to the mean variance approach. 1. Introduction to Portfolio Optimization Portfolio optimization plays a critical role in determining portfolio strategies for investors. What investors hope to achieve from portfolio optimization is to maximize portfolio returns and minimize portfolio risk. Since return is compensated based on risk, investors have to balance the risk-return tradeoff for their investments. Therefore, there is no a single optimized portfolio that can satisfy all investors. An optimal portfolio is determined by an investor’s risk-return preference. -
Modern Portfolio Theory, Part One
Modern Portfolio Theory, Part One Introduction and Overview Modern Portfolio Theory suggests that you can maximize your investment returns, given the amount of risk (or volatility) you are willing to take on. This is the idea to be developed and evaluated during this 10-part series. Part One provides an introduction to the issues. by Donald R. Chambers e are inundated with advice ory” or MPT. The most important advances emerged: efficient market Wregarding investment deci- point of MPT is that diversification theory and equilibrium pricing sions from numerous sources (bro- reduces risk without reducing expected theory. kers, columnists, economists) and return. MPT uses mathematics and Led by Professor Eugene Fama, through a variety of media (televi- statistics to demonstrate diversifica- MPT pioneers established a frame- sion, magazines, seminars). But tion clearly and carefully. work for discussing the idea that the suggested answers regarding This series focuses on relatively security markets are informationally investment decisions not only vary simple and easy-to-implement efficient. This means that secu- tremendously but often rity prices already reflect directly conflict with each MPT does not describe or prescribe invest- available information and other—leaving the typical that it is therefore not investor in a quandary. ing perfectly. But even if it’s not perfect, possible to use available On top of this MPT has major implications that should be information to identify complexity, conditions under-priced or over- change. Markets crash considered by every investor. priced securities. and firms once viewed as In the wake of difficult providing solutions, such as Merrill investment concepts. -
Achieving Portfolio Diversification for Individuals with Low Financial
sustainability Article Achieving Portfolio Diversification for Individuals with Low Financial Sustainability Yongjae Lee 1 , Woo Chang Kim 2 and Jang Ho Kim 3,* 1 Department of Industrial Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Korea; [email protected] 2 Department of Industrial and Systems Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea; [email protected] 3 Department of Industrial and Management Systems Engineering, Kyung Hee University, Yongin-si 17104, Gyeonggi-do, Korea * Correspondence: [email protected] Received: 5 August 2020; Accepted: 26 August 2020; Published: 30 August 2020 Abstract: While many individuals make investments to gain financial stability, most individual investors hold under-diversified portfolios that consist of only a few financial assets. Lack of diversification is alarming especially for average individuals because it may result in massive drawdowns in their portfolio returns. In this study, we analyze if it is theoretically feasible to construct fully risk-diversified portfolios even for the small accounts of not-so-rich individuals. In this regard, we formulate an investment size constrained mean-variance portfolio selection problem and investigate the relationship between the investment amount and diversification effect. Keywords: portfolio size; portfolio diversification; individual investor; financial sustainability 1. Introduction Achieving financial sustainability is a basic goal for everyone and it has become a shared concern globally due to increasing life expectancy. Low financial sustainability may refer to individuals with low financial wealth, as well as investors with a lack of financial literacy. Especially for individuals with limited wealth, financial sustainability after retirement is a real concern because of uncertainty in pension plans arising from relatively early retirement age and change in the demographic structure (see, for example, [1,2]). -
Volatility and the Alchemy of Risk
Volatility and the Alchemy of Risk Reflexivity in the Shadows of Black Monday 1987 Christopher Cole The Ouroboros, a Greek word meaning ‘tail debt expansion, asset volatility, and financial Artemis Capital Managment devourer’, is the ancient symbol of a snake engineering that allocates risk based on that consuming its own body in perfect symmetry. volatility. In this self-reflexive loop volatility The imagery of the Ouroboros evokes the can reinforce itself both lower and higher. In infinite nature of creation from destruction. The a market where stocks and bonds are both sign appears across cultures and is an important overvalued, financial alchemy is the only way to icon in the esoteric tradition of Alchemy. feed our global hunger for yield, until it kills the Egyptian mystics first derived the symbol very system it is nourishing. from a real phenomenon in nature. In extreme The Global Short Volatility trade now heat a snake, unable to self-regulate its body represents an estimated $2+ trillion in financial temperature, will experience an out-of-control engineering strategies that simultaneously exert spike in its metabolism. In a state of mania, the influence over, and are influenced by, stock snake is unable to differentiate its own tail from market volatility.2 We broadly define the short its prey, and will attack itself, self-cannibalizing volatility trade as any financial strategy that until it perishes. In nature and markets, when relies on the assumption of market stability to randomness self-organizes into too perfect generate returns, while using volatility itself symmetry, order becomes the source of chaos.1 as an input for risk taking. -
Optimization of Conditional Value-At-Risk
Implemented in Portfolio Safeguard by AORDA.com Optimization of conditional value-at-risk R. Tyrrell Rockafellar Department of Applied Mathematics, University of Washington, 408 L Guggenheim Hall, Box 352420, Seattle, Washington 98195-2420, USA Stanislav Uryasev Department of Industrial and Systems Engineering, University of Florida, PO Box 116595, 303 Weil Hall, Gainesville, Florida 32611-6595, USA A new approach to optimizing or hedging a portfolio of ®nancial instruments to reduce risk is presented and tested on applications. It focuses on minimizing conditional value-at-risk CVaR) rather than minimizing value-at-risk VaR),but portfolios with low CVaR necessarily have low VaR as well. CVaR,also called mean excess loss,mean shortfall,or tail VaR,is in any case considered to be a more consistent measure of risk than VaR. Central to the new approach is a technique for portfolio optimization which calculates VaR and optimizes CVaR simultaneously. This technique is suitable for use by investment companies,brokerage ®rms,mutual funds, and any business that evaluates risk. It can be combined with analytical or scenario- based methods to optimize portfolios with large numbers of instruments,in which case the calculations often come down to linear programming or nonsmooth programming. The methodology can also be applied to the optimization of percentiles in contexts outside of ®nance. 1. INTRODUCTION This paper introduces a new approach to optimizing a portfolio so as to reduce the risk of high losses. Value-at-risk VaR) has a role in the approach, but the emphasis is on conditional value-at-risk CVaR), which is also known as mean excess loss, mean shortfall, or tail VaR. -
Liquidity Effects in Options Markets: Premium Or Discount?
Liquidity Effects in Options Markets: Premium or Discount? PRACHI DEUSKAR1 2 ANURAG GUPTA MARTI G. SUBRAHMANYAM3 March 2007 ABSTRACT This paper examines the effects of liquidity on interest rate option prices. Using daily bid and ask prices of euro (€) interest rate caps and floors, we find that illiquid options trade at higher prices relative to liquid options, controlling for other effects, implying a liquidity discount. This effect is opposite to that found in all studies on other assets such as equities and bonds, but is consistent with the structure of this over-the-counter market and the nature of the demand and supply forces. We also identify a systematic factor that drives changes in the liquidity across option maturities and strike rates. This common liquidity factor is associated with lagged changes in investor perceptions of uncertainty in the equity and fixed income markets. JEL Classification: G10, G12, G13, G15 Keywords: Liquidity, interest rate options, euro interest rate markets, Euribor market, volatility smiles. 1 Department of Finance, College of Business, University of Illinois at Urbana-Champaign, 304C David Kinley Hall, 1407 West Gregory Drive, Urbana, IL 61801. Ph: (217) 244-0604, Fax: (217) 244-9867, E-mail: [email protected]. 2 Department of Banking and Finance, Weatherhead School of Management, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106-7235. Ph: (216) 368-2938, Fax: (216) 368-6249, E-mail: [email protected]. 3 Department of Finance, Leonard N. Stern School of Business, New York University, 44 West Fourth Street #9-15, New York, NY 10012-1126. Ph: (212) 998-0348, Fax: (212) 995-4233, E- mail: [email protected].