Modeling seasonality in agricultural commodity futures

The stochastic behavior of agricultural commodity prices is investigated using observations of the term structures of futures prices over time. The continuous time dynamics of (log‐) commodity prices are modeled as a sum of a deterministic seasonal component, a non‐stationary state‐variable, and a stationary state‐variable. Futures prices are established by standard no‐arbitrage arguments and the Kalman filter methodology is used to estimate the model parameters for corn futures, soybean futures, and wheat futures based on weekly data from the Chicago Board of Trade for the period 1972–1997. Furthermore, in a discussion of the estimated seasonal patterns in agricultural commodity prices, the paper provides empirical evidence on the theory of storage that predicts a negative relationship between stocks of inventory and convenience yields; in particular, convenience yields used in this analysis are extracted using the Kalman filter. © 2002 Wiley Periodicals, Inc. Jrl Fut Mark 22:393–426, 2002     

Arbitrage,cointegration, and the joint dynamics of prices across discrete commodity futures auctions

Underlying the search for arbitrage opportunities across commodity futures markets that differ in market structure is the idea that the futures prices for similar commodities that are traded on different exchanges adjusted for differences in currency, delivery time (if any), location, and market structure are equal. This article examines price linkages in competing discrete commodity futures auction markets. We find no evidence of cointegration of futures prices of similar commodities traded on two contemporaneous discrete auction futures exchanges in Asia. We also find no evidence of arbitrage activities across these two Asian exchanges, though this does not preclude arbitrage activities with North American continuous auction markets. This lack of cointegration may be due to nonstationarities in the trading cost component. © 1999 John Wiley & Sons, Inc. Jrl Fut Mark 19: 799–815, 1999     

浅析套期保值中棉花套利的应用

套保套利是指以规避现货价格风险为目的的期货交易行为.企业开展套保套利交易,是将期货市场当作转移价格风险的场所,利用期货合约作为将来在现货市场上买卖商品的临时替代物,对其现在买进但准备以后售出的商品或对将来需要买进的商品的价格进行"锁定"的交易活动.套保套利的本质在于"风险对冲"和"风险转移".     

Commodity Markets and Commodity Mutual Funds

Fundamental economic factors—market demand and supply conditions—provide the most consistent explanation for trends in commodity prices from 2004 to 2011. This paper presents empirical evidence that the rise and fall of commodity prices on a monthly basis can be strongly linked to the value of the U.S. dollar and the world business cycle—in particular, to the strength or weakness in emerging market economies such as China, Brazil, India, and Russia. Despite concerns raised by some policymakers that increased commodity index investment (the financialization of commodities) has driven commodity price movements, numerous academic studies have concluded that index-based investing has not moved prices or exacerbated volatility in commodity markets in recent years. An examination of weekly and monthly net flows into commodity mutual funds reveals that these flows have little or no effect on the overall growth rate of commodity prices. In particular, weekly flows into commodity mutual funds do not lead to future commodity price changes. These results are consistent with academic papers that find little or no impact of commodity index investors on commodity prices in individual markets. The paper concludes by briefly discussing three key factors that illustrate why flows into commodity mutual funds cannot explain commodity price movements.     

ARBITRAGE AND INFORMATION IN A SEQUENTIAL ECONOMY WITH MANY CREDIT AGENCIES

This paper augments the theoretical foundations of organized commodity futures markets and uncovers singular facts about arbitrage and the role of information. Using the term "credit agency" to embrace organized futures markets such as the Chicago Board of Trade as well as independent brokerage houses, we extend the extant theory of temporary equilibrium for an economy with a single credit agency to economies with many credit agencies. In the process, we find that arbitrage with no risk of bankruptcy and with perfect interagency trade information can be incompatible with equilibrium (exact or approximate). On the other hand, the usual regularity assumptions are sufficient for the existence of at least an approximate equilibrium, provided that interagency trade information is imperfect (or risky). However, such imperfect information limits arbitrage so different agencies can have different prices.     

Country-of-Origin Premiums for Retailers in International Trades: Evidence from eBay's International Markets

Using real-world transaction prices in the Internet auction Web site eBay's U.S., U.K., and global markets, the authors study the price dispersion of homogeneous products related to the sellers’ country-of-origin. For both tangible and intangible products and services, sellers from the United States enjoy a price premium. This premium appears to stem from country-of-origin equity instead of trading risk or product quality. The findings of this research suggest potential profitable opportunities in international trade by employing the retailer's country-of-origin as an arbitrage tool.     

The profitability of index futures arbitrage: Evidence from bid-ask quotes

Previous studies investigated the profitability of stock index futures based on transaction price data, and could overstate the frequency of arbitrage opportunities and size of arbitrage profits. This article obtains a data base for the Hong Kong index futures and index options market that contains both real-time transaction prices and bid-ask quotes; the article further examines the bias of identifying arbitrage opportunities based on transaction prices. The article finds the percentage of observations violating no-arbitrage bounds is significantly reduced when bid-ask quotes are employed instead of transaction prices. This suggests studies that implement arbitrage strategies based on transaction prices employ prices from the wrong side of the spread. This article finds a relationship between the frequency of violations (evaluated from transaction prices) and the size of bid-ask spreads in the futures and options markets. This phenomenon indicates that a larger mispricing, which may arise when the bid-ask spread is wider, does not necessarily imply profitable arbitrage opportunity. © 1998 John Wiley & Sons, Inc. Jrl Fut Mark 18:743–763, 1998     

BRAZIL-UNITED STATES TRADE: CAPITAL FLIGHT THROUGH ABNORMAL PRICING

Detailed analysis of the statistics of merchandise trade between Brazil and the United States reveals extensive underpricing of exports and overpricing of imports, which has the effect of transferring large amounts of money out of Brazil and into the United States. Previous studies called attention to this possibility without being able to demonstrate convincingly the extent and amount of the practice. This paper reports the results of a systematic investigation of U.S. customs data at its most disaggregate level to document the amount of capital flows which may be hidden in commodity trade. Using deviations from average prices within commodity classes to identify abnormal prices produces conservative estimates of the amount of capital flight from Brazil to the United States of between $2 to $4 billion in 1995 alone, which would be between 10%-20% of total commodity trade between the countries in that year. Some suggestions are developed for using the results to more closely monitor international transactions in order to reduce this amount.     

A Study of Arbitrage Efficiency Between the FTSE‐100 Index Futures and Options Contracts

Despite the importance of the London markets and the significance of the relationship for market makers, little published research is available on arbitrage between the FTSE‐100 Index futures and the FTSE‐100 European index options contracts. This study uses the put–call–futures parity condition to throw light on the relationship between options and futures written against the FTSE Index. The arbitrage methodology adopted in this study avoids many of the problems that have affected prior research on the relationship between options or futures prices and the underlying index. The problems that arise from nonsynchroneity between options and futures prices are reduced by the matching of options and futures prices within narrow time intervals with time‐stamped transaction data. This study allows for realistic trading and market‐impact costs. The feasibility of strategies such as execute‐and‐hold and early unwinding is examined with both ex‐post and ex‐ante simulation tests that take into consideration possible execution time lags for the arbitrage trade. This study reveals that the occurrence of matched put–call–futures trios exhibits a U‐shaped intraday pattern with a concentration at both open and close, although the magnitude of observed mispricings has no discernible intraday pattern. Ex‐post arbitrage profits for traders facing transaction costs are concentrated in at‐the‐money options. As in other major markets, despite important microstructure differences, opportunities are generally rapidly extinguished in less than 3 min. The results suggest that arbitrage opportunities for traders facing transaction costs are small in number and confirm the efficiency of trading on the London International Financial Futures and Options Exchange. © 2002 John Wiley & Sons, Inc. Jrl Fut Mark 22:31–58, 2002     

THE RANGE OF TRADED OPTION PRICES

Suppose we are given a set of prices of European call options over a finite range of strike prices and exercise times, written on a financial asset with deterministic dividends which is traded in a frictionless market with no interest rate volatility. We ask: when is there an arbitrage opportunity? We give conditions for the prices to be consistent with an arbitrage-free model (in which case the model can be realized on a finite probability space). We also give conditions for there to exist an arbitrage opportunity which can be locked in at time zero. There is also a third boundary case in which prices are recognizably misspecified, but the ability to take advantage of an arbitrage opportunity depends upon knowledge of the null sets of the model.     

Optimal No‐Arbitrage Bounds on S&P 500 Index Options and the Volatility Smile

This article shows that the volatility smile is not necessarily inconsistent with the Black–Scholes analysis. Specifically, when transaction costs are present, the absence of arbitrage opportunities does not dictate that there exists a unique price for an option. Rather, there exists a range of prices within which the option's price may fall and still be consistent with the Black–Scholes arbitrage pricing argument. This article uses a linear program (LP) cast in a binomial framework to determine the smallest possible range of prices for Standard & Poor's 500 Index options that are consistent with no arbitrage in the presence of transaction costs. The LP method employs dynamic trading in the underlying and risk‐free assets as well as fixed positions in other options that trade on the same underlying security. One‐way transaction‐cost levels on the index, inclusive of the bid–ask spread, would have to be below six basis points for deviations from Black–Scholes pricing to present an arbitrage opportunity. Monte Carlo simulations are employed to assess the hedging error induced with a 12‐period binomial model to approximate a continuous‐time geometric Brownian motion. Once the risk caused by the hedging error is accounted for, transaction costs have to be well below three basis points for the arbitrage opportunity to be profitable two times out of five. This analysis indicates that market prices that deviate from those given by a constant‐volatility option model, such as the Black–Scholes model, can be consistent with the absence of arbitrage in the presence of transaction costs. © 2001 John Wiley & Sons, Inc. Jrl Fut Mark 21:1151–1179, 2001     

Generic Existence and Robust Nonexistence of Numéraires in Finite Dimensional Securities Markets

A numéraire is a portfolio that, if prices and dividends are denominated in its units, admits an equivalent martingale measure that transforms all gains processes into martingales. We first supply a necessary and sufficient condition for the generic existence of numéraires in a finite dimensional setting. We then characterize the arbitrage‐free prices and dividends for which the absence of numéraires survives any small perturbation preserving no arbitrage. Finally, we identify the cases when any small, but otherwise arbitrary, perturbation of prices and dividends preserves either the existence of numéraires, or their nonexistence under no arbitrage.     

Pricing by Arbitrage Under Arbitrary Information

A substantial applications literature on pricing by arbitrage has effectively restricted information to that arising solely from securities markets; return distributions are then governed solely by past prices. We reconsider pricing by arbitrage in markets rendered incomplete by arbitrary information, which, moreover, may influence required returns. We show that contingent claims depending solely on securities' normalized price histories are priced by arbitrage if and only if all risk-adjusted probabilities agree upon the law of primitive securities' normalized prices. We show how existing diffusion-based results can be preserved, and resolve an issue relating to Merton's (1973) stochastic interest rate model.     

Arbitrage with Fractional Brownian Motion

Fractional Brownian motion has been suggested as a model for the movement of log share prices which would allow long–range dependence between returns on different days. While this is true, it also allows arbitrage opportunities, which we demonstrate both indirectly and by constructing such an arbitrage. Nonetheless, it is possible by looking at a process similar to the fractional Brownian motion to model long–range dependence of returns while avoiding arbitrage.     

ARBITRAGE BOUNDS FOR PRICES OF WEIGHTED VARIANCE SWAPS

We develop a theory of robust pricing and hedging of a weighted variance swap given market prices for a finite number of co‐maturing put options. We assume the put option prices do not admit arbitrage and deduce no‐arbitrage bounds on the weighted variance swap along with super‐ and sub‐replicating strategies that enforce them. We find that market quotes for variance swaps are surprisingly close to the model‐free lower bounds we determine. We solve the problem by transforming it into an analogous question for a European option with a convex payoff. The lower bound becomes a problem in semi‐infinite linear programming which we solve in detail. The upper bound is explicit. We work in a model‐independent and probability‐free setup. In particular, we use and extend Föllmer's pathwise stochastic calculus. Appropriate notions of arbitrage and admissibility are introduced. This allows us to establish the usual hedging relation between the variance swap and the “log contract” and similar connections for weighted variance swaps. Our results take the form of a FTAP: we show that the absence of (weak) arbitrage is equivalent to the existence of a classical model which reproduces the observed prices via risk‐neutral expectations of discounted payoffs.     

PRICE‐ADMISSIBILITY CONDITIONS FOR ARBITRAGE‐FREE LINEAR PRICE FUNCTION MODELS FOR THE TERM STRUCTURE OF INTEREST RATES

To assure price admissibility—that all bond prices, yields, and forward rates remain positive—we show how to control the state variables within the class of arbitrage‐free linear price function models for the evolution of interest rate yield curves over time. Price admissibility is necessary to preclude cash‐and‐carry arbitrage, a market imperfection that can happen even with a risk‐neutral diffusion process and positive bond prices. We assure price admissibility by (i) defining the state variables to be scaled partial sums of weighted coefficients of the exponential terms in the bond pricing function, (ii) identifying a simplex within which these state variables remain price admissible, and (iii) choosing a general functional form for the diffusion that selectively diminishes near the simplex boundary. By assuring that prices, yields, and forward rates remain positive with tractable diffusions for the physical and risk‐neutral measures, an obstacle is removed from the wider acceptance of interest rate methods that are linear in prices.     

Optimal investment,derivative demand,and arbitrage under price impact

This paper studies the optimal investment problem with random endowment in an inventory‐based price impact model with competitive market makers. Our goal is to analyze how price impact affects optimal policies, as well as both pricing rules and demand schedules for contingent claims. For exponential market makers preferences, we establish two effects due to price impact: constrained trading and nonlinear hedging costs. To the former, wealth processes in the impact model are identified with those in a model without impact, but with constrained trading, where the (random) constraint set is generically neither closed nor convex. Regarding hedging, nonlinear hedging costs motivate the study of arbitrage free prices for the claim. We provide three such notions, which coincide in the frictionless case, but which dramatically differ in the presence of price impact. Additionally, we show arbitrage opportunities, should they arise from claim prices, can be exploited only for limited position sizes, and may be ignored if outweighed by hedging considerations. We also show that arbitrage‐inducing prices may arise endogenously in equilibrium, and that equilibrium positions are inversely proportional to the market makers' representative risk aversion. Therefore, large positions endogenously arise in the limit of either market maker risk neutrality, or a large number of market makers.     

THE EFFECT OF TRADING FUTURES ON SHORT SALE CONSTRAINTS

It is commonly believed that the trading of futures on a commodity enables the market to overcome short selling constraints on the spot commodity itself. This belief is embedded in the notion that trading strategies involving futures contracts enable traders to replicate the payoffs as if they were short the spot commodity. The purpose of this paper is to investigate this common belief in a general arbitrage‐free semimartingale financial model with trading in futures and a short selling prohibition on the spot commodity. We show via various examples that, in general, this common belief is incorrect. Furthermore, we provide a set of sufficient conditions, albeit very restrictive, under which the common belief is true.     

Integration and arbitrage in the Spanish financial markets: An empirical approach*

Several authors have introduced different ways to measure integration between financial markets. Most of them are derived from the basic assumptions about asset prices, like the Law of One Price or the absence of arbitrage opportunities. Two perfectly integrated markets must give identical prices to identical final payoffs, and a vector of positive discount factors, common to both markets, must exist. If these properties do not hold, the degree to which they are violated can be defined and considered as a measure of integration. The present paper empirically tests integration measures in the Spanish financial markets. Furthermore, the integration measures are operationalized to analyze the presence of cross‐market arbitrage without previously specifying the exact nature of the arbitrage strategy to be used. When the absence of arbitrage holds, several interesting variables are obtained, for instance, state prices or risk‐neutral probabilities. When this absence fails, explicit cross‐market arbitrage portfolios are provided. The results of the test yield some evidence about market efficiency and integration outside the United States, and they are surprising for several reasons. First of all, arbitrage opportunities do sometimes appear, and the bid–ask spread and transaction costs seem to be unable to prevent arbitrage profits. Furthermore, the criticisms that are usually raised when empirical papers show the existence of arbitrage opportunities do not apply here because we work with perfectly synchronized high frequency data. On the other hand, different integration measures show a similar evolution along the tested period, although these measures give different information about the markets’ efficiency and integration, and they do not necessarily have to be related. © 2000 John Wiley & Sons, Inc. Jrl Fut Mark 20: 321–344, 2000     

NO‐ARBITRAGE PRICING UNDER SYSTEMIC RISK: ACCOUNTING FOR CROSS‐OWNERSHIP

We generalize Merton’s asset valuation approach to systems of multiple financial firms where cross‐ownership of equities and liabilities is present. The liabilities, which may include debts and derivatives, can be of differing seniority. We derive equations for the prices of equities and recovery claims under no‐arbitrage. An existence result and a uniqueness result are proven. Examples and an algorithm for the simultaneous calculation of all no‐arbitrage prices are provided. A result on capital structure irrelevance for groups of firms regarding externally held claims is discussed, as well as financial leverage and systemic risk caused by cross‐ownership.