Research articles for the 2019-02-27

A review of two decades of correlations, hierarchies, networks and clustering in financial markets
Gautier Marti,Frank Nielsen,Mikołaj Bińkowski,Philippe Donnat

This document is an ongoing review on the state of the art of clustering financial time series and the study of correlation and other interaction networks. This preliminary document is intended for researchers in this field so that they can feedback to allow amendments, corrections and addition of new material unknown to the authors of this review. The aim of the document is to gather in one place the relevant material that can help the researcher in the field to have a bigger picture, the quantitative researcher to play with this alternative modeling of the financial time series, and the decision maker to leverage the insights obtained from these methods. We hope that this document will form a basis for implementation of an open toolbox of standard tools to study correlations, hierarchies, networks and clustering in financial markets.

An analysis of cryptocurrencies conditional cross correlations
Nektarios Aslanidis,Aurelio F. Bariviera,Oscar Martinez-Ibañez

This letter explores the behavior of conditional correlations among main cryptocurrencies, stock and bond indices, and gold, using a generalized DCC class model. From a portfolio management point of view, asset correlation is a key metric in order to construct efficient portfolios. We find that: (i) correlations among cryptocurrencies are positive, albeit varying across time; (ii) correlations with Monero are more stable across time; (iii) correlations between cryptocurrencies and traditional financial assets are negligible.

Art Market Bubbles, Limited Art Supply and Collectors' Wealth
Bernales, Alejandro,Reus, Lorenzo,Valdenegro, Víctor
We examine the unexplored effect on art markets of limited art supply and collectors' wealth under short-sale constraints and risk-aversion. Speculative bubbles increase with reductions in the art supply, more negative correlation between collators' wealth and the 'emotional' value of artworks, and rises in heterogeneous beliefs. However, the sources of speculation also increase the art price variance; thus, agents require a larger price discount to hold artworks. Consequently, the net impact of speculation is not necessarily to increase art prices. Moreover, we show that the sources of speculation in artworks increase the expected turnover rate and the price change variance.

Between Scylla and Charybdis: Income Distribution, Consumer Credit, and Business Cycles
Cardaci, Alberto,Saraceno, Francesco
We introduce a macroeconomic model with heterogeneous households and an aggregate banking sector in order to analyze the impact of rising income inequality under different credit scenarios. Growing inequality produces debt‐led consumption boom dynamics when the banking sector is characterized by a lower capital requirement and a higher willingness to lend. Instead, when inequality rises but the banking sector is highly regulated, aggregate demand and output fall. Our results also yield new insights on the appropriate fiscal policy reaction to stabilize the economy: acting on the progressivity of the tax system seems more effective than a proactive countercyclical fiscal policy.

Bid-Ask Spread and Liquidity Searching Behaviour of Informed Investors in Option Markets
Bernales, Alejandro,Cañón, Carlos,Verousis, Thanos
We show evidence of a liquidity searching behaviour of informed investors in option listings, which was also found by Collin-Dufresne and Fos (2015) using stock markets. Nevertheless, and differently from Collin-Dufresne and Fos (2015), we find that the option bid-ask spread may be still a good proxy for informed trading, despite of the liquidity searching behaviour of informed agents. We show an upward trend in the option bid-ask spread after option introductions (as informed traders avoid trading in initial periods after listing dates due to the low liquidity environment), which is steeper for options with high chances of information asymmetries.

CVaR Constrained Planning of Renewable Generation with Consideration of System Inertial Response, Reserve Services and Demand Participation
Inzunza, Andrés,Moreno, Rodrigo,Bernales, Alejandro,Rudnick, Hugh
Integration of renewable generation can lead to both diversification of energy sources (which can improve the overall economic performance of the power sector) and cost increase due to the need for further resources to provide flexibility and thus secure operation from unpredictable, variable and asynchronous generation. In this context, we propose a cost-risk model that can properly plan generation and determine efficient technology portfolios through balancing the benefits of energy source diversification and cost of security of supply through provision of various generation frequency control and demand side services, including preservation of system inertia levels. We do so through a scenario-based cost minimization framework where the conditional value at risk (CVaR), associated with costs under extreme scenarios of fossil fuel prices combined with hydrological inflows, is constrained. The model can tackle problems with large data sets (e.g. 8760 hours and 1000 scenarios) since we use linear programming and propose a Benders-based method adapted to deal with CVaR constraints in the master problem. Through several analyses, including the Chilean main electricity system, we demonstrate the effects of renewables on hedging both fossil fuel and hydrological risks; effects of security of supply on costs, risks and renewable investment; and the importance of demand side services in limiting risk exposure of generation portfolios through encouraging risk mitigating renewable generation investment.

Changing Business Models in International Bank Funding
Gambacorta, Leonardo,Rixtel, Adrian Van,Schiaffi, Stefano
This paper investigates the foreign funding mix of globally active banks. Using BIS international banking statistics for a panel of 12 advanced economies, we detect a structural break in international bank funding at the onset of the great financial crisis. In their postbreak business model, banks rely less on cross‐border liabilities and, instead, tap funds from outside their jurisdictions by making more active use of their subsidiaries and branches, as well as interoffice accounts within the same banking group.

Characterizing Cryptocurrency market with Levy's stable distributions
Shinji Kakinaka,Ken Umeno

Recent emergence of cryptocurrencies such as Bitcoin and Ethereum has posed possible alternatives to global payments as well as financial assets around the globe, making investors and financial regulators aware of the importance to modeling them properly. The Levy's stable distribution is one of the attractive distribution that well describes the fat tails and scaling phenomena in economic systems. In this paper, we show that the behaviors of price fluctuations in cryptocurrency markets can also be characterized by a Levy's stable distribution under certain conditions of time intervals ranging from 30 minutes to 4 hours. The arguments are developed under the theoretical background of the General Central Limit Theorem (GCLT) and quantitative valuation defined as a distance function using the Parseval's relation. Our approach can generally be extended for further analysis of statistical properties and applications for financial modeling.

Civil Disobedience in Latter-Day Saint Thought
Oman, Nathan B.
The Church of Jesus Christ of Latter-day Saints is one of the largest of the religious traditions born in the United States. What is the role of civil disobedience in the Latter-day Saint thought? Some passages in the scriptures of the church suggests an almost unlimited obligation to comply with secular law. In other places, the Latter-day Saint canon suggests a more limited duty of obedience, one that is broadly speaking contingent on the legal system being what might be called “a nearly just regime.” In practice, when pushed by a hostile state, the Saints have been willing to declare if “the laws of my country should come in contact with the laws of God …I shall invariably choose the latter.” However, history also reveals that the calculus for Latter-day Saints has never been this simple. Church leaders have generally counseled obedience to unjust laws coupled with engagement to improve them. More tellingly, in the face of at times suspicious and vicious governments, Latter-day Saints have been counseled to obey the law as a way of protecting themselves and their community from predatory state actors. In short, their religion does not provide the Latter-day Saints with any neat or clear answer to the perennial question of where to draw the line between the claims of God and the claims of Caesar. Rather, it gives them a native tradition within which to consider such questions.

Collateralized-Uncollateralized Funding Decision in Money Markets
Bernales, Alejandro,Cañón, Carlos,Garrido, Nicolás
Little is known about the factors that affect banks' relative preferences for collateralized and uncollateralized funding. We examine the determinants of the collateralized-uncollateralized funding decision using a unique dataset. We decompose the relative collateralized-uncollateralized funding activity into migrations and co-movements, including the directions of funding flows. Migrations and co-movements depend on various determinants, such as systemic risk, collateral availability, central bank policies and the inter-bank network structure. Interestingly, migrations and co-movements behave differently in periods of high financial stress, because safe assets (used as collateral to reduce counterparty risk) are then no longer perceived as completely safe.

Colors, Emotions, and the Auction Value of Paintings
Ma, Marshall (Xiaoyin),Noussair, Charles N.,Renneboog, Luc
We study the impact of colors of paintings on prices in the art auction market and incorporate color attributes of non-figurative paintings in pricing models. A one standard deviation increase in the percentages of blue (red) hue leads to premiums of 10.63% (4.20%). We also conduct laboratory experiments in China, the Netherlands, and U.S., and elicit participants’ willingness-to-pay and emotions (pleasure-arousal). Blue (red) paintings command 18.57% (17.28%) higher bids and stronger intention to purchase. Although abstract art is visually arousing, it is the emotional pleasure channel that relates colors and prices. Our results are consistent across all three cultures.

Cryptoasset Factor Models
Zura Kakushadze

We propose factor models for the cross-section of daily cryptoasset returns and provide source code for data downloads, computing risk factors and backtesting them out-of-sample. In "cryptoassets" we include all cryptocurrencies and a host of various other digital assets (coins and tokens) for which exchange market data is available. Based on our empirical analysis, we identify the leading factor that appears to strongly contribute into daily cryptoasset returns. Our results suggest that cross-sectional statistical arbitrage trading may be possible for cryptoassets subject to efficient executions and shorting.

Do Investors Follow the Herd in Option Markets?
Bernales, Alejandro,Verousis, Thanos,Voukelatos, Nikolaos
We investigate the previously unexplored herding behaviour of investors in option markets, by examining equity option contracts traded in the US between 1996 and 2012. We document strong herding effects in option trading activity that are conditional on a set of systematic factors related to periods of market stress. More specifically, we find that option investors tend to herd during periods of high market volatility risk, on dates of macroeconomic announcements, during the financial crisis of 2008, when a large number of market option positions is either opened or closed, and during periods of a large average dispersion of analysts’ forecasts.

Exchange Rates, Foreign Currency Exposure and Sovereign Risk
Bernoth, Kerstin,Herwartz, Helmut
We quantify the causal link between exchange rate movements and sovereign risk of 16 major emerging market economies (EMEs) by means of structural vector autoregressive models (SVARs) using data from 10/2004 through 12/2016. We apply a novel data based identification approach of the structural shocks that allows to account for the complex interrelations within the triad of exchange rates, sovereign risks and interest rates. We find that the direction and size of the response of sovereign risk to FX rate movements depend on the type of exchange rate measure we look at and on the size of the net foreign currency exposure of an economy. A depreciation of the domestic currency against the USD increases sovereign risk. In contrast, a depreciation of the effective exchange rate turns out to have only a significant effect on sovereign risk for countries with large negative net foreign currency exposures of the private sector. In this case, a depreciation of the NEER also induces an increase in sovereign risk. We conclude that the `financial channel' is more important in the transmission of exchange rate shocks to sovereign risk in comparison with the traditional `net trade channel'.

Expected Returns and Risk in the Stock Market
Brennan, Michael J.,Taylor, Alex P.
We present new evidence on the predictability of aggregate market returns by developing two new prediction models, one risk-based, and the other purely statistical. The pricing kernel model expresses the expected return as the covariance of the market return with a pricing kernel that is a linear function of portfolio returns. The discount rate model predicts the expected return directly as a function of weighted past portfolio returns. These models provide independent evidence of predictability, with R2 of 16-19% for 1-year returns. We show that innovations in the pricing kernel are associated with the cash flow component of the market return.

Fed’s Unconventional Monetary Policy and Risk Spillover in the US Financial Markets
Balcilar, Mehmet,Ozdemir, Zeynel Abidin,Ozdemir, Huseyin,Wohar, Mark E.
This study examines volatility spillover dynamics among the S&P 500 index, the US 10-year Treasury yield, the US dollar index futures and the commodity price index. The focus of the study is to analyze effects of Fed’s unconventional monetary policy on the US financial markets. We use realized volatility measures based on daily data covering the period from December 29, 1996 to November 12, 2018. To address nonlinear and asymmetric spillover dynamics in low and high volatility states, we propose a new regime-dependent spillover index based on a smooth transition vector autoregressive (STVAR) model, extending the study of Diebold and Yilmaz (2009,2012) to regime switching models. When applied to US financial data, we find strong evidence that the US financial market risk structure changes after the announcement of quantitively easing (QE) through the portfolio balance channel. The risk spillover moves from purchased assets to non-purchased assets after the QE announcements.

Financial Development and Manufacturing Output Growth Nexus in Nigeria: The Role of Institutional Quality
Aminu, Alarudeen,Raifu, Isiaka Akande,Oloyede, Bolanle Deborah
This study examines the mediating role of institutional quality in the relationship between financial development and manufacturing output in Nigeria during the period from 1984 to 2016. To achieve this objective, autoregressive distributed lag method (ARDL) is used to determine the short-run and long-run effects of financial development and that of its interaction with institutional quality indicators (democratic accountability, bureaucratic quality and control of corruption) on manufacturing output. The findings show that financial development contributes positively to manufacturing output in the long-run. However, this contribution is moderated downwards by institutional quality indicators. Against the background of the findings, it is recommended that government should develop a policy framework that will allow for a proper integration of financial sector with what goes on in the manufacturing sector and that government should also encourage some sort of harmonious working relationship among relevant institutions in both sectors for the development of manufacturing sector.

Fintech and Banking
Thakor, Anjan V.
This paper is a review of fintech and its interaction with banking. Included in fintech are innovations in payment systems (including cryptocurrencies), credit markets (including P2P lending), and insurance, with blockchain-assisted smart contract playing a role. The paper provides a definition of fintech, examines some statistics and stylized facts, and then reviews the theoretical and empirical literature. The review is organized around four main research questions. That paper summarizes our knowledge on these questions and concludes with questions for future research.

Firm Life Cycle, Expectation Errors and Future Stock Returns
Konstantinidi, Theodosia
I study the return predictability of firm life cycle, originally documented by Dickinson (2011). I show that a hedge portfolio strategy going long on mature firms and short on introduction firms generates a significant hedge portfolio return of 1.4% per month in return-weighted portfolios and 0.75% in value-weighted portfolios. The returns to firm life cycle are related to investors’ and analysts’ expectation errors, are driven by market-wide investor sentiment, and are more pronounced among stocks with low institutional ownership and high idiosyncratic volatility. Overall, my evidence is consistent with a mispricing-based explanation for the firm life cycle effect in returns.

Global Collateral and Capital Flows
Fostel, Ana,Geanakoplos, John,Phelan, Gregory
Cross-border financial flows arise when (otherwise identical) countries differ in their abilities to use assets as collateral to back financial contracts. Financially integrated countries have access to the same set of financial instruments, and yet there is no price convergence of assets with identical payoffs, due to a gap in collateral values. Home (financially advanced) runs a current account deficit. Financial flows amplify asset price volatility in both countries, and gross flows driven by collateral differences collapse following bad news about fundamentals. Our results can explain financial flows among rich, similarly-developed countries, and why these flows increase volatility.

How Do Americans Repay Their Debt? The Balance-Matching Heuristic
Gathergood, John,Mahoney, Neale,Stewart, Neil,Weber, Joerg
In Gathergood et al. (forthcoming), we studied credit card repayments using linked data on multiple cards from the United Kingdom. We showed that individuals did not allocate payments to the higher interest rate card, which would minimize the cost of borrowing, but instead made repayments according to a balance-matching heuristic under which the share of repayments on each card is matched to the share of balances on each card. In this paper, we examine whether these results extend to the United States using a large sample of TransUnion credit bureau data. These data do not provide information on interest rates, so we cannot examine the optimality of payments. However, we observe balances and repayments, so we can examine balance-matching behavior. We replicate our analysis and find that Americans also repay their debt in accordance with a balance-matching heuristic.

Investor Experiences and Financial Market Dynamics
Ulrike Malmendier,Demian Pouzo,Victoria Vanasco

How do macro-financial shocks affect investor behavior and market dynamics? Recent evidence on experience effects suggests a long-lasting influence of personally experienced outcomes on investor beliefs and investment, but also significant differences across older and younger generations. We formalize experience-based learning in an OLG model, where different cross-cohort experiences generate persistent heterogeneity in beliefs, portfolio choices, and trade. The model allows us to characterize a novel link between investor demographics and the dependence of prices on past dividends, while also generating known features of asset prices, such as excess volatility and return predictability. The model produces new implications for the cross-section of asset holdings, trade volume, and investors' heterogenous responses to recent financial crises, which we show to be in line with the data.

Learning and Forecasts about Option Returns through the Volatility Risk Premium
Bernales, Alejandro,Chen, Louisa,Valenzuela, Marcela
We use learning in an equilibrium model to explain the puzzling predictive power of the volatility risk premium (VRP) for option returns. In the model, a representative agent follows a rational Bayesian learning process in an economy under incomplete information with the objective of pricing options. We show that learning induces dynamic differences between probability measures P and Q, which produces predictability patterns from the VRP for option returns. The forecasting features of the VRP for option returns, obtained through our model, exhibit the same behaviour as those observed in an empirical analysis with S&P 500 index options.

Linear Credit Risk Models
Damien Ackerer,Damir Filipović

We introduce a novel class of credit risk models in which the drift of the survival process of a firm is a linear function of the factors. The prices of defaultable bonds and credit default swaps (CDS) are linear-rational in the factors. The price of a CDS option can be uniformly approximated by polynomials in the factors. Multi-name models can produce simultaneous defaults, generate positively as well as negatively correlated default intensities, and accommodate stochastic interest rates. A calibration study illustrates the versatility of these models by fitting CDS spread time series. A numerical analysis validates the efficiency of the option price approximation method.

Make-Take Decisions under High-Frequency Trading Competition
Bernales, Alejandro
Make-take preferences of investors depend on high-frequency trading (HFT) competition, under which HFT firms endogenously acquire speed and information advantages. In the case where there are many HFT firms in the market, they compete more through limit orders; meanwhile, in the case with few HFT firms, they compete more through market orders that ‘pick off’ limit orders coming from the big crowd of slow traders. In the former (latter) case, additional HFT competition improves (damage) liquidity. In both cases, HFT competition improves informational efficiency and reduces microstructure noise. Finally, we use the model to analyze potential regulations under HFT competition.

Managing Risk Taking with Interest Rate Policy and Macroprudential Regulations
Cociuba, Simona,Shukayev, Malik,Ueberfeldt, Alexander
We develop a model in which a financial intermediary's investment in risky assets—risk taking—is excessive due to limited liability and deposit insurance, and characterize the policies that implement efficient risk taking. In the calibrated model, combining interest rate policy with state‐contingent macroprudential regulations—either capital or leverage regulation, and a tax on profits—achieves efficiency. Interest rate policy mitigates excessive risk taking by altering the return and the supply of collateralizable safe assets. In contrast to commonly used capital regulation, leverage regulation has stronger effects on risk taking and calls for higher interest rates.

Mean-field moral hazard for optimal energy demand response management
Romuald Elie,Emma Hubert,Thibaut Mastrolia,Dylan Possamaï

We study the problem of demand response contracts in electricity markets by quantifying the impact of considering a mean-field of consumers, whose consumption is impacted by a common noise. We formulate the problem as a Principal-Agent problem with moral hazard in which the Principal - she - is an electricity producer who observes continuously the consumption of a continuum of risk-averse consumers, and designs contracts in order to reduce her production costs. More precisely, the producer incentivises the consumers to reduce the average and the volatility of their consumption in different usages, without observing the efforts they make. We prove that the producer can benefit from considering the mean-field of consumers by indexing contracts on the consumption of one Agent and aggregate consumption statistics from the distribution of the entire population of consumers. In the case of linear energy valuation, we provide closed-form expression for this new type of optimal contracts that maximises the utility of the producer. In most cases, we show that this new type of contracts allows the Principal to choose the risks she wants to bear, and to reduce the problem at hand to an uncorrelated one.

Over-the-Counter Market Liquidity and Securities Lending
Foley-Fisher, Nathan,Gissler, Stefan,Verani, Stephane
This paper studies how over-the-counter market liquidity is affected by securities lending. We combine micro-data on corporate bond market trades with securities lending transactions and individual corporate bond holdings by U.S. insurance companies. Applying a difference-in-differences empirical strategy, we show that the shutdown of AIG's securities lending program in 2008 caused a statistically and economically significant reduction in the market liquidity of corporate bonds predominantly held by AIG. We also show that an important mechanism behind the decrease in corporate bond liquidity was a shift towards relatively small trades among a greater number of dealers in the interdealer market.Online Appendix: Online Appendix - Further Robustness Tests

Q-Gaussian diffusion in stock markets
Alonso-Marroquin Fernando,Arias-Calluari Karina,Harre Michael,Najafi Morteza N.,Herrmann Hans J

We analyze the Standard & Poor's 500 stock market index from the last 22 years. The probability density function of price returns exhibits two well-distinguished regimes with self-similar structure: the first one displays strong super-diffusion together with short-time correlations, and the second one corresponds to weak super-diffusion with weak time correlations. Both regimes are well-described by q-Gaussian distributions. The porous media equation is used to derive the governing equation for these regimes, and the Black-Scholes diffusion coefficient is explicitly obtained from the governing equation.

Quantum model for price forecasting in financial markets
J. L. Subias

The present paper describes a practical example in which the probability distribution of the prices of a stock market blue chip is calculated as the wave function of a quantum particle confined in a potential well. This model may naturally explain the operation of several empirical rules used by technical analysts. Models based on the movement of a Brownian particle do not account for fundamental aspects of financial markets. This is due to the fact that the Brownian particle is a classical particle, while stock market prices behave more like quantum particles. When a classical particle meets an obstacle or a potential barrier, it may either bounce or overcome the obstacle, yet not both at a time. Only a quantum particle can simultaneously reflect and transmit itself on a potential barrier. This is precisely what prices in a stock market imitate when they find a resistance level: they partially bounce against and partially overcome it. This can only be explained by admitting that prices behave as quantum rather than as classic particles. The proposed quantum model finds natural justification not only for the aforementioned facts but also for other empirically well-known facts such as sudden changes in volatility, non-Gaussian distribution in prices, among others.

Safe Assets: Made, Not Just Born
McCauley, Robert N.
Official reserve managers have a big stake in the debate over safe assets: their portfolios just about define such assets. This paper conveys the message that reserve managers need not worry about a shortage of safe assets. The debate turns first on whether demand for dollar safe assets will grow as rapidly as emerging market economies (EMEs). Second, it turns on whether the supply of dollar safe assets only grows with US fiscal deficits. Neither holds. On the demand side, EMEs' growth does not require ever higher dollar reserves. Indeed, the global economy may have reached "peak reserves" in 2014. On the supply side, law and policy extend state backing to various IOUs, thereby creating safe assets. US government support for the housing agencies Fannie Mae and Freddie Mac has made their debt into safe assets, albeit with wobbles. Federal Reserve liquidity, Federal Deposit Insurance Corporation insurance, and, in extremis as in 2008, Treasury equity also work to make US bank deposits safe. Elsewhere, government support of banks allows those from well rated countries to compete with US banks in issuing safe dollar deposits. Moreover, supranational organisations, non-US sovereigns and their agencies all compete with the US Treasury in issuing safe dollar bonds. In allocating their dollar foreign exchange reserves, central banks make room for such competitors. In particular, they hold more than a third of such reserves in instruments other than US Treasury securities.

The Role of National Debts in the Determination of the Yen‐Dollar Exchange Rate
Litsios, Ioannis,Pilbeam, K.
An intertemporal optimization model is developed to examine the determinants of the long‐run nominal yen‐dollar exchange rate in the presence of national debts. The model is tested empirically using data from Japan and the United States. The proposed theoretical specification is well supported by the data and shows that relative national debts as well as monetary and financial factors may play a significant role in the determination of the long‐run nominal exchange rate between the yen and the dollar.

Time Reversal and Last Passage Time of Diffusions with Applications to Credit Risk Management
Masahiko Egami,Rusudan Kevkhishvili

We study time reversal, last passage time, and $h$-transform of linear diffusions. For general diffusions with killing, we obtain the probability density of the last passage time to an arbitrary level and analyze the distribution of the time left until killing after the last passage time. With these tools, we develop a new risk management framework for companies based on the leverage process (the ratio of a company asset process over its debt) and its corresponding alarming level. We also suggest how a company can determine the alarming level for the leverage process by constructing a relevant optimization problem.

Underreporting of Bank Risk: Does Shareholder-Manager Distance Matter?
Flanagan, Thomas,Purnanandam, Amiyatosh K.
Using a regulatory change that forced commercial banks in India to reveal the extent of hidden non-performing loans (NPLs), we show that banks hide more when their shareholders are distant. Specifically, banks with higher shareholding by foreign institutional investors (FIIs) engage in higher underreporting. These effects are stronger for banks with highly compensated CEOs. Analyzing the period leading up to the regulatory change, we find that CEO's compensation was more tightly linked to observable performance measures such as profitability and NPLs for banks with high FII shareholding. Managers of these banks responded by reporting lower NPLs, in part by engaging in untruthful reporting. Distant shareholder should use caution in deploying high-powered compensation contracts linked to observable performance measures as a substitute for diluted monitoring: instead of solving the agency problem, it can result in perverse misreporting incentives.

Volatility Forecasting Across Tanker Freight Rates: The Role of Oil Price Shocks
Gavriilidis, Konstantinos,Kambouroudis, Dimos S,Tsakou, Katerina,Tsouknidis, Dimitris A.
This paper examines whether the inclusion of oil price shocks of different origin as exogenous variables in a wide set of GARCH-X models improves the accuracy of their volatility forecasts for spot and 1-year time-charter tanker freight rates. Kilian’s (2009) oil price shocks of different origin enter GARCH-X models which, among other stylized facts of the tanker freight rates examined, take into account the presence of asymmetric and long-memory effects. The results reveal that the inclusion of aggregate oil demand and oil-specific (precautionary) demand shocks improves significantly the accuracy of the volatility forecasts drawn.

What Do We Know About Individual Equity Options?
Bernales, Alejandro,Verousis, Thanos,Voukelatos, Nikolaos,Zhang, Mengyu
This paper examines the empirical literature on equity options, highlighting main findings and providing a guide for future research. Key topics include the impact of equity option listings on the underlying stock market, options market efficiency, the market microstructure of the equity options market, option price discovery, private information revealed in equity option prices, and new research trends on equity options in terms of option returns and investors' behaviours that depart from rationality. Some directions for future research include the determinants of equity option returns and the effect of algorithmic trading in options markets.