异质信念、投机均衡与农产品期货定价*

农产品期货市场套利并不充分,交易者也不是完全理性的。本文假设农产品期货市场有限套利、交易者异质信念并遵循“经验法则”预期,构建了农产品期货投机均衡定价模型,并认为集中竞价规则下产生的农产品期货价格是由交易者的预期决定的;前期期货价格水平、现货价格和前期期货价格的变动趋势、不同类型交易者的比例结构及其预期模式共同影响农产品期货价格的形成与波动;基本分析法交易者占主导地位的农产品期货市场具有更高的套期保值与价格发现效率。针对中国七种主要农产品期货的实证结果显示,农产品期货投机均衡定价模型对解释中国农产品期货价格的形成与波动是有效的。这意味着在期货行情系统中实时披露现货价格信息,培育和引导交易者运用基本分析法预测期货价格走势,有助于提升农产品期货市场的效率。     

Volatility–volume co-movements: evidence from China metal markets

This article investigates the interactional relationship between price volatility and futures trading activity for three heavily traded metal products on the Shanghai Metal Exchange and the Shanghai Futures Exchange. Using models based on vector autoregression and generalized method of moments, we show, in particular, that futures trading activity has a strong impact on both spot and futures price volatility in copper and aluminium markets. Futures trading activity leads spot market volatility in copper and aluminium markets which suggests that futures markets have a destabilizing effect. In order to disentangle the effect of different traders’ types on asset price movements, we decompose futures trading into speculators’ and hedgers’ trading and investigate their contributions to volatility. As a robustness check, we investigate the impact of endogenous structural breaks on the interactional relationship between price volatility and futures trading.     

Can Markets Learn to Avoid Bubbles?

One of the most striking results in experimental economics is the ease with which market bubbles form in a laboratory setting and the difficulty of preventing them. This article re-examines bubble experiments in light of the results of an earlier series of market experiments that show how learning occurs in markets characterized by an asymmetry of information between buyers and sellers, such as found in Akerlof's lemons model and Spence's signaling model. Markets with asymmetric information are incomplete because they lack markets for specific levels of product quality. Such markets either lump all qualities together (lemons) or using external indications of quality to separate them (signaling). Similarly, the markets used in bubble experiments are incomplete in that they are lacking a complete set of forward or futures markets, depriving traders of the information supplied by the prices in those markets. Preliminary experimental results suggest that the addition of a single forward market can sometimes mitigate bubble formation and this article suggests more extensive research in this direction is warranted. Market bubbles outside of the laboratory usually are found in markets in which forward and futures markets are either legally restricted or otherwise limited. Experimentation in markets with asymmetric information also indicates that the ability of subjects to learn how to send and receive signals can be enhanced by changing the way that market information is presented to them. We explore how this result might be used to help asset markets learn to avoid bubbles     

Effects of electronic trading on the Hang Seng Index futures market

This investigation of the switch from open-outcry trading to electronic trading on the Hang Seng Index (HSI) futures contract reveals that the bid–ask spread narrows and the futures price plays more of a role in information transmission. Factors, such as anonymity in trading and fast order execution in electronic trading, attract informed traders to the futures market, enhancing the information flow. Our results provide support for the worldwide trend of transforming open-outcry markets into electronic trading platforms.     

Returns to individual traders in agricultural futures markets: skill or luck?

Using individual trader data from the Commodity Futures Trading Commission's (CFTC) Large Trader Reporting System (LTRS) for the period January 2000 to September 2009, this article investigates whether noncommercial traders in the corn, live cattle and coffee futures markets persist in making profits. Two out-of-sample measures of skill – a winner and a loser ranking test and a top and a bottom decile test – are used to analyse the ability of traders to consistently perform well at monthly, quarterly and annual time horizons. The findings identify significant persistence in rankings – traders in the top half of the profit distribution in a time period tend to stay in the top half in the next period. Differences in magnitude of profitability between the top and bottom deciles also provide support that persistent skill exists among the top 10% of traders. Detailed examination of annual rankings for those traders who were most continuously in the markets further reveals persistence in profits for a smaller subset of traders, as well as an indication of persistence in the face of losses.     

Dynamic Relationships among GCC Stock Markets and Nymex Oil Futures

Daily relationships among stock markets of the Gulf Cooperation Council (GCC) members, excluding Qatar, form two equilibrium relationships with varying predictive power. The Saudi market leads, followed by Bahrain and United Arab Emirates. Kuwait, which is dominated by momentum traders, and Oman have the weakest links with the other GCC markets. Only the Saudi index can predict—and be predicted by—New York Mercantile Exchange oil futures prices. Therefore these markets are candidates for diversified regional portfolios at the country level. The trading day effect is weak for all GCC markets and oil futures prices but remains consistent with findings for the U.S. stock market. (JEL C22 , F3 , Q49 )     

Price Limits, Information Acquisition, and Bid–ask Spreads: Theory and Evidence

A number of futures markets use price limits which, in effect, preclude trade from occurring at prices outside certain exogenous bounds. Noting that such markets are characterized by heterogeneously informed traders, whereas previous work on price limits assumes symmetrically informed traders, we examine the effects of price limits in a setting where market participants are asymmetrically informed. We find that imposing price limits generally lowers the quality of information acquired in equilibrium, but lowers bid–ask spreads as well. Thus, depending on the relative weights placed by society on liquidity versus price efficiency, there may exist a set of price limits that are most efficient in achieving a trade-off between liquidity and informational efficiency. We perform empirical tests of some implications of the model using cross-sectional data on price limits. We find that price limits are strongly negatively related to both price volatility and trading volume. Though other explanations for our empirical findings cannot be ruled out, these results are not inconsistent with the model's implication that price limits should be tighter for contracts which offer greater profit potential for informed traders.     

Trading platform,market volatility and pricing efficiency in the floor-traded and E-mini index futures markets

This study examines the pricing efficiency of E-mini and floor-traded index futures under electronic versus open-outcry trading platforms. By using OLS and quantile regressions to control for changes in market characteristics, we find that pricing errors are smaller in the E-mini markets than the floor-traded markets, thereby confirming that electronic trading has special attractions for arbitrageurs and informed traders. However, during periods of higher volatility, the advantages of speedier execution, anonymity and information efficiency may be offset by arbitrage risks; as a result, larger pricing errors are observed in the E-mini markets. We provide new evidence confirming the important roles in pricing efficiency played by both traditional open-outcry systems and electronic trading systems.     

“Overreaction” of Asset Prices in General Equilibrium

We attempt to explain the overreaction of asset prices to movements in short-term interest rates, dividends, and asset supplies. The key element of our explanation is a margin constraint that traders face which limits their leverage to a fraction of the value of their assets. Traders may lever themselves, furthermore, either directly by borrowing short term or indirectly by engaging in futures and options trading, so that the scenario is relevant to contemporary financial markets. When some shock pushes asset prices to a low enough level at which the margin constraint binds, traders are forced to liquidate assets. This drives asset prices below what they would be with frictionless markets. Also, a shock which simply increases the likelihood that the margin constraint will bind can have a very similar effect on asset prices. We construct a general equilibrium model with margin constrained traders and derive some qualitative properties of asset prices. We present an analytical solution for a deterministic version of the model and a simple numerical computation of the stochastic version.Journal of Economic LiteratureClassification Numbers: G1, E0.     

Don’t let your robots grow up to be traders: Artificial intelligence, human intelligence, and asset-market bubbles

Researchers who have examined markets populated by “robot traders” have claimed that the high level of allocative efficiency observed in experimental markets is driven largely by the “intelligence” implicit in the rules of the market. Furthermore, they view the ability of agents (artificial or human) to process information and make rational decisions as unnecessary for the efficient operation of markets. This paper presents a new series of market experiments that show that markets populated with standard robot traders are no longer efficient if time is a meaningful element, as it is in all asset markets. While simple two-season markets with human subjects reliably converge to an efficient equilibrium, markets with minimally intelligent robot traders fail to attain this equilibrium. Instead, these markets overshoot the equilibrium and then crash below it. In addition to firmly establishing the role of trader intelligence in asset-market equilibrium, these experiments also provide insights into why bubbles and crashes are consistently observed in many asset-market laboratory experiments using human subjects.     

Intermarket spread opportunities between Canadian and American agricultural futures

This study extends Carter's (1989) study of the efficiency of Canadian canola and American soybean oil futures markets during 1981–1987 to a new period (1988–1993). It also uses a different spread strategy than Carter to see if the same conclusions hold for canola and soybean as well as Canadian feed wheat and American wheat futures. Our findings confirm that in the 1981–1987 period there were no opportunities for intermarket spread profit between canola and soybean oil futures and between feed wheat and wheat futures. Our findings for the period 1988–1993, however, suggest there were some opportunities for such profits. Thus, it was possible for floor traders (and possibly institutional investors), who paid low transaction costs, to experience some additional profits. We also find that these opportunities are neither due to changes in currency values over time, nor to the use of weekly or daily exchange rates. Nevertheless, nonparametric tests show that spread profits are statistically insignificant.     

Order Flows,Investor Sentiments and Feedback Trade in Index Futures Market

This paper examines the presence of feedback trading, and investor sentiment drove feedback trading by traders in the Nifty 50 index futures contract in India. The results of the study using high-frequency data sampled at 10 min interval using VAR and contemporaneous VAR model as applied to market microstructure settings reveals negative evidence of feedback trade and investor sentiment-driven feedback trade in Nifty 50 futures contract. Further, consistency with noise trading hypothesis, order flows in Nifty 50 futures contract is less informative when traders are overly optimistic.

     

Strategic noise traders and liquidity pressure with a physically deliverable futures contract

Do physically deliverable futures contracts induce liquidity pressure in the underlying spot market? The answer is believed to be no since the asset is delivered sometimes after the expiration of the contract so that the futures trader's payoff does not clearly depend on the price of the underlying stock at expiration. We construct a rational expectations equilibrium model in which a strategic uninformed trader induces liquidity pressure in the underlying spot market at the expiration of a physically deliverable futures contract. Liquidity pressure is the result of a pure informational advantage: if it is known that futures traders hedge their position in the spot market then a strategic trader with no information about the fundamental value of the underlying has an incentive to create noise in the futures market in order to gain information on the composition of the spot order flow at future auctions. We show that informed traders benefit from this form of strategic noise and that the efficiency of the prices remains unaffected.     

Simultaneity, Rationality and Price Determination in US Live Cattle

The results of recent research on the informational efficiency of the US live cattle futures market are ambiguous. Moreover, simultaneous, rational expectations models of spot and futures markets for non-storables are lacking in the literature. This paper addresses both issues: by developing a simultaneous rational expectations model of the US live cattle market, with functional relationships for short hedgers, long hedgers, net short speculators and consumers, the paper employs a wider information set than in previous research and it thus provides a more powerful test of the efficient market hypothesis (EMH). Tests indicate the possible presence of non-linearities in the long hedging and net short speculation equations.
The results suggest first, that there is support for Working's hypotheses of selective and operational hedging, for short and long hedgers respectively, second that speculators may be noise traders or risk-loving (although the non-linear version of the speculation function partially corrects this anomaly), and third that beef is a normal good while corn is a complementary input. Time-varying volatility is represented as an EGARCH ( p , q ) process. Post-sample, this model does not significantly outperform the futures price in spot price forecasting, implying non-rejection of the EMH.     

Is the corn futures market noisier? The impact of high frequency quoting

ABSTRACT

The paper pioneers research on high frequency (HF) quoting noise in electronically traded agricultural futures markets. HF quoting – quickly cancelling posted limit orders and replacing them with new ones – emerges as a strategy for liquidity-providing traders. HF quoting can generate noise in price quotes which adds uncertainty to order execution and impairs the informational value of bid and ask prices. It can also lead to the perception that markets cannot be trusted for commercial transactions. Using intraday Best Bid Offer data for 2008–2013 and wavelet-based measures of volatility, we investigate the excess variance and co-movement discrepancies in the bid and ask prices. We find excess HF quoting variance exists. It is the highest at 250-ms scale – 90% higher than the variance implied by a random walk – but declines quickly to 7% at the 32 s scale. But its economic magnitude is negligibly small. Bid and ask price co-movements show a low degree of discrepancy with average correlations at 0.67 at 250 ms and reaching 0.95 at 8 s. All measures indicate that HF quoting noise has declined through the period. Overall, HF quoting has not caused excess variance during the transition to electronic trading in the liquid corn futures market.     

Experimental asset markets with endogenous choice of costly asymmetric information

Asymmetric distribution of information, while omnipresent in real markets, is rarely considered in experimental financial markets. We present results from experiments where subjects endogenously choose between five information levels (four of them costly). We find that (i) uninformed traders earn the highest net returns, while average informed traders always perform worst even when information costs are not considered; (ii) over time traders learn to pick the most advantageous information levels (full information or no information); and (iii) market efficiency decreases with higher information costs. These results are mostly in line with the theoretical predictions of Grossman and Stiglitz (Am. Econ. Rev. 70:393–408, 1980) and provide additional insights that studies with only two information levels cannot deliver.     

Speculative securities

Summary. A speculative security is an asset whose payoff depends in part on a random shock uncorrelated with economic fundamentals (a sunspot) about which some traders have superior information. In this paper we show that agents may find it desirable to trade such a security in spite of the fact that it is a poorer hedge against their endowment risks at the time of trade, and has an associated adverse selection cost. In the specific institutional setting of innovation of futures contracts, we show that a futures exchange may not have an incentive to introduce a speculative security even when all traders favor it. Received: July 19, 1998; revised version: August 31, 1998     

The Effects of Subject Pool and Design Experience on Rationality in Experimental Asset Markets

Empirical evidence suggests that prices do not always reflect fundamental values and individual behavior is often inconsistent with rational expectations theory. We report the results of fourteen experimental asset markets designed to examine whether the interactive effect of subject pool and design experience (i.e., previous experience in a market under identical conditions) tempers price bubbles and improves forecasting ability. Our main findings are: 1) price run-ups are modest and dissipate quickly when traders are knowledgeable about financial markets and have participated in a previous market under identical conditions; 2) price bubbles moderate quickly when only a subset of traders are knowledgeable and experienced; 3) the heterogeneity of expectations about price changes is smaller in markets with knowledgeable and experienced traders, even if such traders only represent a subset of the market; and 4) individual forecasts of prices are not consistent with the predictions of the rational expectations model in any market, although absolute forecast errors are smaller for subjects who are knowledgeable of financial markets and for those subjects who have participated in a previous market. In sum, our findings suggest that markets populated by at least a subset of knowledgeable and experienced traders behave rationally, even though average individual behavior can be characterized as irrational.     

中国期货市场有效性研究

本文介绍了期货市场有效性理论，利用Johansen市场拟合检测方法分析国内两个主要农产品期货品种——大豆和小麦的期货价格和现货价格表现，结果显示大豆的期货价格和现货价格较长时间是一致的，大豆期货市场是有效的．但大豆期货市场仅仅短期有效，小麦期货市场则是无效的。     

Conservative traders,natural selection and market efficiency

This paper examines the impact of conservative traders on market efficiency in an evolutionary model of a commodity futures market. This paper shows that the long-run market outcome is informationally efficient, as long as in every period there is a positive probability that entering traders are more conservative than their predecessors. Conservative traders are those who correctly predict the spot price with a positive probability, and more importantly, who in their mistakes err on the side of caution, and rarely overpredict the spot price as buyers, and underpredict the spot price as sellers. This result does not require entry of traders with better information than their predecessors.