Incentive Compatibility and Differentiability New Results and Classic Applications

We provide several generalizations of Mailath's (1987) result that in games of asymmetric information with a continuum of types incentive compatibility plus separation implies differentiability of the informed agent's strategy. The new results extend the theory to classic models in finance such as Leland and Pyle (1977), Glosten (1989), and DeMarzo and Duffie (1999), that were not previously covered

Stock Market Manipulation and Its Regulation

More than eighty years after federal law first addressed stock market manipulation, the federal courts remain fractured by disagreement and confusion concerning manipulation law\u27s most foundational issues. There remains, for example, a sharp split among the federal circuits concerning manipulation law\u27s central question: Whether trading activity alone can ever be considered illegal manipulation under federal law? Academics have been similarly confused-economists and legal scholars cannot agree on whether manipulation is even possible in principle, let alone on how to properly address it in practice

The New Stock Market: Sense and Nonsense

How stocks are traded in the United States has been totally transformed. Gone are the dealers on NASDAQ and the specialists at the NYSE. Instead, a company’s stock can now be traded on up to sixty competing venues where a computer matches incoming orders. High-frequency traders (HFTs) post the majority of quotes and are the preponderant source of liquidity in the new market. Many practices associated with the new stock market are highly controversial, as illustrated by the public furor following the publication of Michael Lewis’s book Flash Boys. Critics say that HFTs use their speed in discovering changes in the market and in altering their orders to take advantage of other traders. Dark pools – off-exchange trading venues that promise to keep the orders sent to them secret and to restrict the parties allowed to trade – are accused of operating in ways that injure many traders. Brokers are said to mishandle customer orders in an effort to maximize the payments they receive for sending trading venues their customers’ orders, rather than delivering best execution. In this Article, we set out a simple, but powerful, conceptual framework for analyzing the new stock market. The framework is built upon three basic concepts: adverse selection, the principal-agent problem, and a multivenue trading system. We illustrate the utility of this framework by analyzing the new market’s eight most controversial practices. The effects of each practice are evaluated in terms of the multiple social goals served by equity-trading markets. We ultimately conclude that there is no emergency requiring immediate, poorly considered action. Some reforms proposed by critics, however, are clearly desirable. Other proposed reforms involve a trade-off between two or more valuable social goals. In these cases, whether a reform is desirable may be unclear, but a better understanding of the trade-off involved enables a more informed choice and suggests areas in which further empirical research would be useful. Finally, still other proposed reforms are based on misunderstandings of the market or of the social impacts of a practice and should be avoided

High‐Frequency Trading and the New Stock Market: Sense And Nonsense

The stock market has been transformed during the last 25 years. Human suppliers of liquidity like the NASDAQ dealers and NYSE specialists have been replaced by algorithmic market making; stocks that once traded on a single venue now trade across twelve exchanges and a multitude of alternative trading systems. New venues like dark pools, and new participants like high‐frequency traders, have emerged to take on prominent roles. This new market has had more than its share of controversy and regulatory scrutiny, particularly in the wake of Michael Lewis’s bestseller Flash Boys. In this article, the authors analyze five of the most controversial new market practices, including various high‐frequency trading strategies and dark pool activities. They set out a simple conceptual framework based on adverse selection and agency problems, and apply that framework to assess the welfare effects of each of the five practices. While much that is criticized is indeed objectionable, other controversial practices are much more complex than popularly imagined and may in fact be socially desirable. They conclude by evaluating a range of potential reforms to equity market structure

Stock Market Manipulation and Its Regulation

More than eighty years after federal law first addressed stock market manipulation, federal courts remain fractured by disagreement and confusion about manipulation law\u27s most foundational questions. Only last year, plaintiffs petitioned the Supreme Court to resolve a sharp split among the federal circuits concerning manipulation law\u27s central question: whether trading activity alone can ever be considered illegal manipulation under federal law. Academics have been similarly confused economists and legal scholars cannot agree on whether manipulation is possible in principle; let alone on how, if it is, to address it properly in practice

High‐Frequency Trading and the New Stock Market: Sense And Nonsense

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142455/1/jacf12260.pd

Intraday Patterns in the Cross-section of Stock Returns

Motivated by the literature on investment flows and optimal trading, we examine intraday predictability in the cross-section of stock returns. We find a striking pattern of return continuation at half-hour intervals that are exact multiples of a trading day, and this effect lasts for at least 40 trading days. Volume, order imbalance, volatility, and bid-ask spreads exhibit similar patterns, but do not explain the return patterns. We also show that short-term return reversal is driven by temporary liquidity imbalances lasting less than an hour and bid-ask bounce. Timing trades can reduce execution costs by the equivalent of the effective spread

Principal Regression Analysis and the index leverage effect

We revisit the index leverage effect, that can be decomposed into a volatility effect and a correlation effect. We investigate the latter using a matrix regression analysis, that we call `Principal Regression Analysis' (PRA) and for which we provide some analytical (using Random Matrix Theory) and numerical benchmarks. We find that downward index trends increase the average correlation between stocks (as measured by the most negative eigenvalue of the conditional correlation matrix), and makes the market mode more uniform. Upward trends, on the other hand, also increase the average correlation between stocks but rotates the corresponding market mode {\it away} from uniformity. There are two time scales associated to these effects, a short one on the order of a month (20 trading days), and a longer time scale on the order of a year. We also find indications of a leverage effect for sectorial correlations as well, which reveals itself in the second and third mode of the PRA.Comment: 10 pages, 7 figure

Distributed Ledger Technology and the Securities Markets of the Future: A Stakeholder Survey

This Article evaluates the implications of distributed ledger technology (DLT) for the securities markets of the future and their regulation. DLT is an integral part of the larger revolution in computing, communication and data storage capacity that has transformed securities markets over the last few decades and promises further radical change in the years to come. The potential of DLT, if it can be realized, could improve the functioning of our securities markets while at the same time sharply reducing costs. Based on an interview survey of about 100 persons who play prominent roles in actually making these markets work or in regulating them, this Article reports on the most important topics and themes that have emerged from the wide range of interviewees’ opinions about the extent to which DLT will affect the future of securities markets and their regulation. A significant number saw the potential for DLT to transform securities markets and market structure, from the possibility of stock trading on DLT to the potential impact on intermediaries, the ordinary retail investor, and on preventing wrongdoing in the stock market. However, key questions remain about implementation and the appetite for making DLT-based changes among both market participants and regulators