Efficient Market Hypothesis

The Efficient Market Hypothesis (EMH) asserts that, at all times, the price of a security reflects all available information about its fundamental value. The implication of the EMH for investors is that, to the extent that speculative trading is costly, speculation must be a loser's game. Hence, under the EMH, a passive strategy is bound eventually to beat a strategy that uses active management, where active management is characterized as trading that seeks to exploit mispriced assets relative to a risk-adjusted benchmark. The EMH has been refined over the past several decades to reflect the realism of the marketplace, including costly information, transactions costs, financing, agency costs, and other real-world frictions. The most recent expressions of the EMH thus allow a role for arbitrageurs in the market who may profit from their comparative advantages. These advantages may include specialized knowledge, lower trading costs, low management fees or agency costs, and a financing structure that allows the arbitrageur to undertake trades with long verification periods. The actions of these arbitrageurs cause liquid securities markets to be generally fairly efficient with respect to information, despite some notable anomalies.

What are the central questions of economics and how do economists tackle them? This book aims to answer these questions in 100 essays, written by economists and selected from "The New Palgrave: A Dictionary of Economics". It shows how economists deal with issues ranging from trade to taxation.

Describes the lives, theories, and legacies of six great minds in finance who changed the way we look at financial markets and equilibrium. Bachelier, Samuelson, Fama, Ross, Tobin, and Shiller; proponents and critics of the market efficiency theories who redefined modern finance, creating the foundation on which all financial analysis rests.

This is an excerpt from the 4-volume dictionary of economics, a reference book which aims to define the subject of economics today. 1300 subject entries in the complete work cover the broad themes of economic theory. This extract concentrates on finance.

The Ascent of Market Efficiency weaves together historical narrative and quantitative bibliometric data to detail the path financial economists took in order to form one of the central theories of financial economics—the influential efficient-market hypothesis—which states that the behavior of financial markets is unpredictable. As the notorious quip goes, a blindfolded monkey would do better than a group of experts in selecting a portfolio of securities, simply by throwing darts at the financial pages of a newspaper. How did such a hypothesis come to be so influential in the field of financial economics? How did financial economists turn a lack of evidence about systematic patterns in the behavior of financial markets into a foundational approach to the study of finance? Each chapter in Simone Polillo's fascinating meld of economics, science, and sociology focuses on these questions, as well as on collaborative academic networks, and on the values and affects that kept the networks together as they struggled to define what the new field of financial economics should be about. In doing so, he introduces a new dimension—data analysis—to our understanding of the ways knowledge advances. There are patterns in the ways knowledge is produced, and The Ascent of Market Efficiency helps us make sense of these patterns by providing a general framework that can be applied equally to other social and human sciences.

Interest in algorithmic trading is growing massively – it’s cheaper, faster and better to control than standard trading, it enables you to ‘pre-think’ the market, executing complex math in real time and take the required decisions based on the strategy defined. We are no longer limited by human ‘bandwidth’. The cost alone (estimated at 6 cents per share manual, 1 cent per share algorithmic) is a sufficient driver to power the growth of the industry. According to consultant firm, Aite Group LLC, high frequency trading firms alone account for 73% of all US equity trading volume, despite only representing approximately 2% of the total firms operating in the US markets. Algorithmic trading is becoming the industry lifeblood. But it is a secretive industry with few willing to share the secrets of their success. The book begins with a step-by-step guide to algorithmic trading, demystifying this complex subject and providing readers with a specific and usable algorithmic trading knowledge. It provides background information leading to more advanced work by outlining the current trading algorithms, the basics of their design, what they are, how they work, how they are used, their strengths, their weaknesses, where we are now and where we are going. The book then goes on to demonstrate a selection of detailed algorithms including their implementation in the markets. Using actual algorithms that have been used in live trading readers have access to real time trading functionality and can use the never before seen algorithms to trade their own accounts. The markets are complex adaptive systems exhibiting unpredictable behaviour. As the markets evolve algorithmic designers need to be constantly aware of any changes that may impact their work, so for the more adventurous reader there is also a section on how to design trading algorithms. All examples and algorithms are demonstrated in Excel on the accompanying CD ROM, including actual algorithmic examples which have been used in live trading.

As an emerging global phenomenon, Islamic economics and the financial system has expanded exponentially in recent decades. Many components of the industry are still unknown, but hopefully, the lack of awareness will soon be stilled. The Handbook of Research on Theory and Practice of Global Islamic Finance provides emerging research on the latest global Islamic economic practices. The content within this publication examines risk management, economic justice, and stock market analysis. It is designed for financiers, banking professionals, economists, policymakers, researchers, academicians, and students interested in ideas centered on the development and practice of Islamic finance.

The efficient markets hypothesis has been the central proposition in finance for nearly thirty years. It states that securities prices in financial markets must equal fundamental values, either because all investors are rational or because arbitrage eliminates pricing anomalies. This book describes an alternative approach to the study of financial markets: behavioral finance. This approach starts with an observation that the assumptions of investor rationality and perfect arbitrage are overwhelmingly contradicted by both psychological and institutional evidence. In actual financial markets, less than fully rational investors trade against arbitrageurs whose resources are limited by risk aversion, short horizons, and agency problems. The book presents and empirically evaluates models of such inefficient markets. Behavioral finance models both explain the available financial data better than does the efficient markets hypothesis and generate new empirical predictions. These models can account for such anomalies as the superior performance of value stocks, the closed end fund puzzle, the high returns on stocks included in market indices, the persistence of stock price bubbles, and even the collapse of several well-known hedge funds in 1998. By summarizing and expanding the research in behavioral finance, the book builds a new theoretical and empirical foundation for the economic analysis of real-world markets.

A new, evolutionary explanation of markets and investor behavior Half of all Americans have money in the stock market, yet economists can’t agree on whether investors and markets are rational and efficient, as modern financial theory assumes, or irrational and inefficient, as behavioral economists believe. The debate is one of the biggest in economics, and the value or futility of investment management and financial regulation hangs on the answer. In this groundbreaking book, Andrew Lo transforms the debate with a powerful new framework in which rationality and irrationality coexist—the Adaptive Markets Hypothesis. Drawing on psychology, evolutionary biology, neuroscience, artificial intelligence, and other fields, Adaptive Markets shows that the theory of market efficiency is incomplete. When markets are unstable, investors react instinctively, creating inefficiencies for others to exploit. Lo’s new paradigm explains how financial evolution shapes behavior and markets at the speed of thought—a fact revealed by swings between stability and crisis, profit and loss, and innovation and regulation. An ambitious new answer to fundamental questions about economics and investing, Adaptive Markets is essential reading for anyone who wants to understand how markets really work.

Updated with a new chapter that draws on behavioral finance, the field that studies the psychology of investment decisions, the bestselling guide to investing evaluates the full range of financial opportunities.