Option pricing with an illiquid underlying asset market

We examine how price impact in the underlying asset market affects the replication of a European contingent claim. We obtain a generalized Black–Scholes pricing PDE and establish the existence and uniqueness of a classical solution to this PDE. Unlike the case with transaction costs, we prove that replication with price impact is always cheaper than superreplication. Compared to the Black–Scholes case, a trader generally buys more stock and borrows more (shorts and lends more) to replicate a call (put). Furthermore, price impact implies endogenous stochastic volatility and an out-of-money option has lower implied volatility than an in-the-money option. This finding has important implications for empirical analysis on volatility smile.     

Dynamics of state price densities

State price densities (SPDs) are an important element in applied quantitative finance. In a Black–Scholes world they are lognormal distributions, but in practice volatility changes and the distribution deviates from log-normality. In order to study the degree of this deviation, we estimate SPDs using EUREX option data on the DAX index via a nonparametric estimator of the second derivative of the (European) call pricing function. The estimator is constrained so as to satisfy no-arbitrage constraints and corrects for the intraday covariance structure in option prices. In contrast to existing methods, we do not use any parametric or smoothness assumptions.     

Crack spread hedging: accounting for time‐varying volatility spillovers in the energy futures markets

Crude oil, heating oil, and unleaded gasoline futures contracts are simultaneously analysed for their effectiveness in reducing price volatility for an energy trader. A conceptual model is developed for a trader hedging the ‘crack spread’. Various hedge ratio estimation techniques are compared to a Multivariate GARCH model that directly incorporates the time to maturity effect often found in futures markets. Modelling of the time‐variation in hedge ratios via the Multivariate GARCH methodology, and thus taking into account volatility spillovers between markets is shown to result in significant reductions in uncertainty even while accounting for trading costs. Copyright © 2002 John Wiley & Sons, Ltd.     

Intertemporal recursive utility and an equilibrium asset pricing model in the presence of Lévy jumps

This paper presents an equilibrium formulation of asset pricing in an environment of mixed Poisson–Brownian information with recursive utility. The optimal portfolio choice problem is studied together with a derivation of Euler equation as necessary condition for optimality. It is further shown that the price processes governed by the Euler equation, together with the market clearing conditions, constitute the equilibrium price processes. Closed form formulas are derived for European call options and for other derivative securities in a particular parameterization of the economy. The derived option pricing formula contain many existing models as special cases, and is potentially useful in explaining the moneyness biasedness associated with Black–Scholes model.     

Multi-step barrier products and static hedging

This paper examines multi-step barrier options with an arbitrary payoff function using extended static hedging methods. Although there have been studies using extended reflection principles to obtain joint distribution functions for barrier options with complex barrier conditions, and static hedging methods to evaluate limited barrier options with well-known payoff functions, we obtain an explicit expression of barrier option price which has a general payoff function under the Black–Scholes framework assumption. The explicit multi-step barrier options prices we discuss in this paper are not only useful in that they can handle different levels and time steps barrier and all types of payoff functions, but can also extend to pricing of barrier options under finite discrete jump–diffusion models with a simple barrier. In the last part, we supplement the theory with numerical examples of various multi-step barrier options under the Black–Scholes or discrete jump–diffusion model for comparison purposes.     

Superhedging under ratio constraint

We consider superhedging of contingent claims under ratio constraint. It has been widely recognized that the minimum cost of superhedging a contingent claim with certain portfolio constraints is equal to the price of a claim with appropriately modified payoff but without constraints. In terms of the backward stochastic differential equation (BSDE) and the variational inequality equation approach, we revisit this result and provide two counterexamples.     

Equal risk pricing under convex trading constraints

In an incomplete market model where convex trading constraints are imposed upon the underlying assets, it is no longer possible to obtain unique arbitrage-free prices for derivatives using standard replication arguments. Most existing derivative pricing approaches involve the selection of a suitable martingale measure or the optimisation of utility functions as well as risk measures from the perspective of a single trader.We propose a new and effective derivative pricing method, referred to as the equal risk pricing approach, for markets with convex trading constraints. The approach analyses the risk exposure of both the buyer and seller of the derivative, and seeks an equal risk price which evenly distributes the expected loss for both parties under optimal hedging. The existence and uniqueness of the equal risk price are established for both European and American options. Furthermore, if the trading constraints are removed, the equal risk price agrees with the standard arbitrage-free price.Finally, the equal risk pricing approach is applied to a constrained Black–Scholes market model where short-selling is banned. In particular, simple pricing formulas are derived for European calls, European puts and American puts.     

Workup

In pure limit-order markets, the use of large orders is discouraged by potential front-runners. This problem can be mitigated by using expandable orders or iceberg orders, or by splitting a large order into smaller ones. An expandable order gives a trader an option to sequentially expand the size of his trade while holding the price fixed. An iceberg order enables a trader to commit to a maximal trade size at some price, without fully revealing that size to other traders. This paper provides a theoretical model of expandable orders and the accompanying quantity negotiation, called (also by practitioners) the “workup”. The workup is ubiquitous in the U.S. and Canadian bond markets and in over-the-counter markets. The model suggests that even when iceberg orders are available, traders will still use the workup if splitting an order is prohibitively costly, front-running is a threat, and the exchange lacks trust.     

A calibration procedure for analyzing stock price dynamics in an agent-based framework

In this paper we introduce a calibration procedure for validating of agent based models. Starting from the well-known financial model of (Brock and Hommes, 1998), we show how an appropriate calibration enables the model to describe price time series. We formulate the calibration problem as a nonlinear constrained optimization that can be solved numerically via a gradient-based method. The calibration results show that the simplest version of the Brock and Hommes model, with two trader types, fundamentalists and trend-followers, replicates nicely the price series of four different markets indices: the S&P 500, the Euro Stoxx 50, the Nikkei 225 and the CSI 300. We show how the parameter values of the calibrated model are important in interpreting the trader behavior in the different markets investigated. These parameters are then used for price forecasting. To further improve the forecasting, we modify our calibration approach by increasing the trader information set. Finally, we show how this new approach improves the model׳s ability to predict market prices.     

Explicit formulas for the minimal variance hedging strategy in a martingale case

We explicitly compute closed formulas for the minimal variance hedging strategy in discrete time of a European option and for the variance of the corresponding hedging error under the hypothesis that the underlying asset is a martingale following a geometric Brownian motion. The formulas are easy to implement, hence the optimal hedge ratio can be employed as a valid substitute of the standard Black–Scholes delta, and the knowledge of the variance of the total error can be a useful tool for measuring and managing the hedging risk.     

Minimum-cost portfolio insurance

Minimum-cost portfolio insurance is an investment strategy that enables an investor to avoid losses while still capturing gains of a payoff of a portfolio at minimum cost. If derivative markets are complete, then holding a put option in conjunction with the reference portfolio provides minimum-cost insurance at arbitrary arbitrage-free security prices. We derive a characterization of incomplete derivative markets in which the minimum-cost portfolio insurance is independent of arbitrage-free security prices. Our characterization relies on the theory of lattice-subspaces. We establish that a necessary and sufficient condition for price-independent minimum-cost portfolio insurance is that the asset span is a lattice-subspace of the space of contingent claims. If the asset span is a lattice-subspace, then the minimum-cost portfolio insurance can be easily calculated as a portfolio that replicates the targeted payoff in a subset of states which is the same for every reference portfolio.     

Bounds for the utility-indifference prices of non-traded assets in incomplete markets

Abstract We consider a special class of financial models with both traded and non-traded assets and show that the utility indifference (bid) price of a contingent claim on a non-traded asset is bounded above by the expectation under the minimal martingale measure. This bound also represents the marginal bid price for the claim. The key conclusion is that the bound and the marginal bid price are independent of both the utility function and initial wealth of the agent. Thus all utility maximising agents charge the same marginal price for the claim. This conclusion is in some sense the opposite conclusion to that of Hubalek and Schachermayer (2001), who show that any price is consistent with some equivalent martingale measure. Mathematics Subject Classification (2000): 91B28, 91B16, 60J70 Journal of Economic Literature Classification: G13     

Do house price developments spillover across euro area countries? Evidence from a global VAR

This paper empirically assesses the prospects for house price spillovers in the euro area, where co-movement in house prices across countries may be particularly relevant given a general trend with monetary union toward increasing linkages in trade, financial markets, and general economic conditions. A global VAR is estimated for three housing demand variables (real house prices, real per capita income, and the cost of borrowing, captured by a real long-term interest rate) on the basis of quarterly data for 7 euro area countries (Belgium, Germany, Ireland, Spain, France, Italy and the Netherlands), which together comprise nearly 90% of euro area GDP, over the period 1971–2009. The results suggest limited house price spillovers in the euro area, albeit with evidence of some overshooting in the first year after the shock, followed by a long run aggregate euro area impact of country-specific changes in real house prices related in part to the country’s economic weight. This contrasts with the impacts of a shock to domestic long-term interest rates, causing a permanent shift in house prices after 2–3 years. Underlying this aggregate development are rather heterogeneous house price spillovers at the country level, with a strong importance for weights – either economic or geographic – in governing their general magnitude. More generally, the impact of financing costs on house prices appears to have grown though time.     

Continuous-time mean-variance portfolio optimization in a jump-diffusion market

In this paper, we take up an approach of (Lindberg, in Bernoulli, 15(2):464–474, 2009) who introduced a new parameterization of the Black–Scholes model that allows for an easy solution of the continuous-time Markowitz mean-variance problem. We generalize the results of (Lindberg, in Bernoulli, 15(2):464–474, 2009) to a jump-diffusion market setting and slightly correct the proof and the assertion of the main result. Further, we demonstrate the implications of the Lindberg parameterization for the stock price drift vector in different market settings, analyse the dependence of the optimal portfolio from jump and diffusion risk and finally indicate how to use the method. We particularly also show how the optimal strategy can be obtained with the restricted use of historical data.     

Corporate hedging and input price risk

Input price variability is an important source of risk for corporations that process raw commodities. Models of optimal input hedging are developed in this paper based on the maximization of managerial expected utility. The relationship between hedging strategies and output decisions is examined to assess the impact of the ability to set output prices on futures market participation. As a firm's ability to set output prices diminishes in the short run, input futures positions increase although the optimal hedge ratio may either increase or decrease. For a perfectly competitive firm, however, shifts in output price caused by input price changes provide a natural cash market hedge of input price risk and reduce the firm's optimal input futures position.     

Price dynamics in public and private housing markets in Singapore

In down-payment constrained housing consumption models, increases in house prices could trigger household mobility decisions in housing markets. This study empirically tests house price dynamics associated with the mobility of households in the public resale and private housing markets in Singapore. The results show that stochastic permanent breaks were found in the public housing resale prices and private housing prices. The relative prices drift apart occasionally, but mean-revert to a long-run fundamental equilibrium. Error correction mechanisms and lagged public housing prices were also found to have significant explanatory effects for price changes in the private housing markets. The results support the hypothesis that household mobility creates co-movements of prices in public and private housing submarkets in the long run.     

Collateral amplification under complete markets

This paper examines the robustness of the Kiyotaki–Moore collateral amplification mechanism to the existence of complete markets for aggregate risk. We show that, when borrowers can hedge against aggregate shocks at fair prices, the volatility of endogenous variables becomes identical to the first best in the absence of credit constraints. The collateral amplification mechanism disappears.To motivate the limited use of contingent contracts, we introduce costs of issuing contingent debt and calibrate them to match the liquidity and safety premia the data. We find that realistic costs of state contingent market participation can rationalize the predominant use of uncontingent debt. Amplification is restored in such an environment.     

The nonlinear price dynamics of U.S. equity ETFs

We investigate the price dynamics of large market-capitalization U.S. equity exchange-traded funds (ETFs) in order to uncover trader motivations and strategy. We show that prices of highly liquid ETFs can deviate significantly from their daily net asset values. By adjusting for changes in valuations, we report the impact of non-classical variables including price trend and volatility using data from 2008 to 2011. We find a cubic nonlinearity in the trend suggesting that traders are not only aware of the underreaction of others, but also self-optimize by anticipating others’ reactions, and sell when the uptrend is stronger than usual.     

Markets with heterogeneous beliefs: A necessary and sufficient condition for a trader to vanish

What does it take to survive in the market? Previous literature has proposed sufficient conditions for a trader to vanish, which depend on pairwise comparisons of traders’ discounted beliefs. We propose a novel condition that focuses on the ratio of traders’ discounted beliefs and (approximate) equilibrium prices. Unlike existing conditions, ours is both necessary and sufficient for a trader to vanish and delivers the exact rate at which vanishing traders lose their consumption shares. As an application, we analyze the performance of two intuitive behavioral strategies: the “Follow the Leader Strategy” that prescribes mimicking the beliefs of the most successful trader, and the “Follow the Market Strategy” that prescribes to use beliefs which coincide with the state price density. Further, we show that the relative performance of vanishing traders cannot be studied in isolation. Our analysis highlights an intuitive point obscured by the existing conditions: trading in financial markets is qualitatively different from bilateral trading.     

A closer look at Black–Scholes option thetas

This paper investigates Black–Scholes call and put option thetas, and derives upper and lower bounds for thetas as a function of underlying asset value. It is well known that the maximum time premium of an option occurs when the underlying asset value equals the exercise price. However, we show that the maximum option theta does not occur at that point, but instead occurs when the asset value is somewhat above the exercise price. We also show that option theta is not monotonic in any of the parameters in the Black–Scholes option-pricing model, including time to maturity. We further explain why the implications of these findings are important for trading and hedging strategies that are affected by the decay in an option’s time premium.