Prohibited Floor Trading Activities Under the Commodity Exchange Act

In algorithmic graph theory, a classic open question is to determine the complexity of the Maximum Independent Set problem on Pt -free graphs, that is, on graphs not containing any induced path on t vertices. So far, polynomial-time algorithms are known only for t≤5 (Lokshtanov et al., in: Proceedings of the twenty-fifth annual ACM-SIAM symposium on discrete algorithms, SODA 2014, Portland, OR, USA, January 5–7, 2014, pp 570–581, 2014), and an algorithm for t=6 announced recently (Grzesik et al. in Polynomial-time algorithm for maximum weight independent set on P6 -free graphs. CoRR, arXiv:1707.05491, 2017). Here we study the existence of subexponential-time algorithms for the problem: we show that for any t≥1 , there is an algorithm for Maximum Independent Set on Pt -free graphs whose running time is subexponential in the number of vertices. Even for the weighted version MWIS, the problem is solvable in 2O(tnlogn√) time on Pt -free graphs. For approximation of MIS in broom-free graphs, a similar time bound is proved. Scattered Set is the generalization of Maximum Independent Set where the vertices of the solution are required to be at distance at least d from each other. We give a complete characterization of those graphs H for which d-Scattered Set on H-free graphs can be solved in time subexponential in the size of the input (that is, in the number of vertices plus the number of edges): If every component of H is a path, then d-Scattered Set on H-free graphs with n vertices and m edges can be solved in time 2O(|V(H)|n+m√log(n+m)) , even if d is part of the input. Otherwise, assuming the Exponential-Time Hypothesis (ETH), there is no 2o(n+m) -time algorithm for d-Scattered Set for any fixed d≥3 on H-free graphs with n-vertices and m-edges

The Opinion Game: Stock price evolution from microscopic market modelling

We propose a class of Markovian agent based models for the time evolution of a share price in an interactive market. The models rely on a microscopic description of a market of buyers and sellers who change their opinion about the stock value in a stochastic way. The actual price is determined in realistic way by matching (clearing) offers until no further transactions can be performed. Some analytic results for a non-interacting model are presented. We also propose basic interaction mechanisms and show in simulations that these already reproduce certain particular features of prices in real stock markets.Comment: 14 pages, 5 figure

Who to listen to: Exploiting information quality in a ZIP-agent Market

Market theory is often concerned only with centralised markets. In this paper, we consider a market that is distributed over a network, allowing us to characterise spatially (or temporally) segregated markets. The effect of this modification on the behaviour of a market populated by simple trading agents was examined. It was demonstrated that an agent’s ability to identify the optimum market price is positively correlated with its network connectivity. A better connected agent receives more information and, as a result, is better able to judge the market state. The ZIP trading agent algorithm is modified in light of this result. Simulations reveal that trading agents which take account of the quality of the information that they receive are better able to identify the optimum price within a market

Do Crises Tear the Fabric of Oil Trade?

In 1990, Iraq invaded Kuwait, touching off an economic, financial, diplomatic, and military crisis associated with a tremendous spike in oil prices and recession in OECD and oil-importing developing countries. But was the Gulf Crisis a disruption? Did it affect the fabric of oil trade? To examine this question, this paper examines the changing role of international trade intermediaries (ITIs, often referred to as “trading companies”) in the oil market. ITIs connect buyers and sellers, serving as the glue that holds many commodity markets together. Oil trading companies have attracted harsh scrutiny form policymakers as a result of allegations regarding their role in the United Nations’ Iraqi Oil-for-Food Program, but minimal scholarly attention. The paper takes advantage of a unique microdatabase on the Brent market. Produced in the U.K. North Sea, Brent Blend is by far the most widely traded crude oil in the international market. Participants in the Brent market are diverse, with the largest traders falling into two categories. The first comprises “industrial MNEs”—companies active in the business of producing or refining crude oil. The second category comprises financial houses and trading companies. This diversity provides an opportunity to test hypotheses regarding behavioral differences across types of companies and geographic origin, before, during, and after the crisis.oil, trading companies, crisis, Brent, North Sea

FUTURES MARKET DEPTH: REVEALED VS. PERCEIVED PRICE ORDER IMBALANCES

In this paper we study futures market depth by examining the price path due to order imbalances thereby allowing us to directly gain insight in the execution costs due to a lack of market depth We propose a two dimensional market depth measure in which the price path due to order imbalances is described by an S-shape function. The proposed market depth measure is applied to transaction specific futures data from Euronext. Subsequently, we examine CBOT traders' perceptions about the price path due to order imbalances and examine the characteristics that are associated with a particular perception. The proposed market depth measure gives guidelines for improving market depth, and can be used to compare competitive futures contracts. It appears that the actual price path due to order imbalances does not match the perceived price path. Traders have various perceptions about the price path due to order imbalances. Dominant perceptions were, S-shape, linear, exponential or zigzag price paths. The differences in traders' perceptions can be traced back to different traders' characteristics among others type of primary futures contract traded, importance of information sources and trading strategy (herd vs. non-herd behavior). The observed disconnect between perceptions and revealed price path due to order imbalances have great implications for market participants who try to minimize execution costs and for the futures exchange management that tries to increase the market depth.Marketing,

Why the Law Hates Speculators: Regulation and Private Ordering in the Market for OTC Derivatives

A wide variety of statutory and common law doctrines in American law evidence hostility towards speculation. Conventional economic theory, however, generally views speculation as an efficient form of trading that shifts risk to those who can bear it most easily and improves the accuracy of market prices. This Article reconciles the apparent conflict between legal tradition and economic theory by explaining why some forms of speculative trading may be inefficient. It presents a heterogeneous expectations model of speculative trading that offers important insights into antispeculation laws in general, and the ongoing debate concerning over-the-counter (OTC) derivatives in particular. Although trading in OTC derivatives is presently largely unregulated, the Commodity Futures Trading Commission recently announced its intention to consider substantively regulating OTC derivatives under the Commodity Exchange Act (CEA). Because the CEA is at heart an antispeculation law, the heterogeneous expectations model of speculation offers policy support for the CFTC\u27s claim of regulatory jurisdiction. This model also, however, suggests an alternative to the apparently binary choice now available to lawmakers (i. e., either regulate OTC derivatives under the CEA, or exempt them). That alternative would be to regulate OTC derivatives in the same manner that the common law traditionally regulated speculative contracts: as permitted, but legally unenforceable, agreements. By requiring derivatives traders to rely on private ordering to ensure the performance of their agreements, this strategy may offer significant advantages in discouraging welfare-reducing speculation based on heterogeneous expectations while protecting more beneficial forms of derivatives trading

Trading institutions and price discovery: the cash and futures markets for crude oil

We provide substantial evidence that the futures market for West Texas Intermediate crude oil increased the short-term volatility of the cash price of crude oil. We show that the variability of prices increased using both published posted prices and transaction prices for producers. This increased volatility in the price of crude oil may reflect information aggregated into the price, an increase the variance of shocks to the price of crude oil, or noise in the futures price that affects the cash price. We present evidence from experiments consistent with the interpretation that information aggregation not feasible in a posted-price market can explain at least part of the increase in variance. This evidence supports the proposition that information not previously aggregated into the cash price for crude oil is at least part of the reason for the greater variability of the cash price after the opening of the futures market and provides at least one example in which a futures market increased the volatility of the cash market, and prices became more efficient.