The efficient market hypothesis and corporate event waves: part II

This article is the second of a two-part series on the efficient market hypothesis corporate event waves. The ideas of market efficiency, or rational theory, and the behavioral hypothesis have been extensively used to explain the modern phenomena of corporate event waves. Some studies investigate the patterns of corporate events from a behavioral finance perspective and suggest that corporate announcement waves are driven by investor sentiment. Baker and Wurgler examine equity market timing as an aspect of real corporate financial policy. Sentiment can also explain IPO waves. Post-announcement returns and IPO volume are positively correlated to firms' capital demands and the level of investor optimism. Helwge and Liang examine the IPO cycles from hot to cold markets from 1975 to 2000. Corporate e vent wave scan also be explained by the neoclassical efficiency hypothesis, proposing that business cycle fluctuations and economic conditions drive firms' decisions on financing transactions.

Testing the weak-form version of the efficient markets hypothesis

This thesis examines the weak-form efficiency of the Australian stock market using data from Australia's major banking stocks, the Banking Index and the All Ordinaries Index. Applying a combination of existing technical analysis indicators, coupled with a relatively new technique known as Sequential (TM) reveals that the Australian stock market is weak-form inefficient.

The efficient market hypothesis and corporate event waves: part 1

Efficient markets are commonly defined as ones that do not allow investors to earn above-average returns without accepting above-average risk. In a traditional framework, where investors are rational and there are no frictions, the efficient market hypothesis (EMH) states that a security's price reflects its fundamental value, which is the sum of its discounted expected future cash flows. Put simply, under the EMH, securities are "rightly priced." Through this study, the author finds that while the EMH has been widely accepted for decades among academics, practitioners and regulators still appear to be unconvinced. From a behavioral perspective, the author shows that human psychology and sentiment factors can account for some discrepancies in financial markets. He also finds evidence of limited arbitrage being risky and costly and, hence, impeding the ability of investors to take advantage of profitable opportunities. This study provides an extensive analysis of the critical discussions surrounding the EMH and deepens and strengthens the understanding of the EMH, as well as the arguments for and against.

Is the efficient market hypothesis day-of-the-week dependent? Evidence from the banking sector

In this article, we propose a new hypothesis: that the efficient market hypothesis is day-of-the-week-dependent. We apply the test to firms belonging to the banking sector and listed on the NYSE. We find significant evidence that the efficient market hypothesis is day-of-the-week-dependent. Overall, for only 62% of firms, the unit root null hypothesis is rejected on all the five trading days. We also discover that when investors do not account for unit root properties in devising trading strategies, they obtain spurious profits.

Is South Korea’s stock market efficient?

This letter applies the Zivot and Andrews (Journal of Business and Economic Statistics, 10, 251-70, 1992) one break and the Lumsdaine and Papell (Review of Economic and Statistics, 79, 212-8, 1997) two break unit root tests to examine the random walk hypothesis for stock prices in South Korea. The results provide strong evidence that stock prices in South Korea are characterized by a unit root, which is consistent with the efficient market hypothesis.

Estimating Forward Pricing Function: How Efficient is Indian Stock Index Futures Market?

This paper uses Indian stock futures data to explore unbiased expectations and efficient market hypothesis. Having experienced voluminous transactions within a short time span after its establishment, the Indian stock futures market provides an unparalleled case for exploring these issues involving expectation and efficiency. Besides analyzing market efficiency between cash and futures prices using cointegration and error correction frameworks, the efficiency hypothesis is also investigated after explicitly modeling the underlying state of the market (expansion or contraction) through the first-order Markov switching set-up. The results based on Markov switching analysis show that relatively longer time horizon is more effective in eliminating arbitrage opportunities than the short run.

Efficiency and unbiasedness in the Indian stock index futures market

This paper explores potential efficiency and unbiasedness as well as the degree of efficiency in stock index futures of an emerging market using both monthly and daily data. Besides analyzing efficiency and unbiasedness with cointegration and error correction model, the degree of efficiency is further investigated after explicitly modeling the underlying state of the market (expansion or contraction) through the first-order Markov switching set-up. The results show that a relatively longer two-month horizon is more effective in eliminating arbitrage opportunities than the short run (one-month and daily) futures.

A GARCH model for testing market efficiency

In this paper we propose a generalised autoregressive conditional heteroskedasticity (GARCH) model-based test for a unit root. The model allows for two endogenous structural breaks. We test for unit roots in 156 US stocks listed on the NYSE over the period 1980 to 2007. We find that the unit root null hypothesis is rejected in 40% of the stocks, and only in four out of the nine sectors the null is rejected for over 50% of stocks. We conclude with an economic significance analysis, showing that mostly stocks with mean reverting prices tend to outperform stocks with non-stationary prices.

Speed of adjustment within currency markets

One measure of market efficiency is the speed at which prices adjust to fundamental value with the arrival of information. This paper examines this issue by estimating speed of adjustment coefficients using three  methodologies for eight currencies for the entire year of 1996 using half hourly non-overlapping return intervals. We find that the bulk of adjustment to fundamental value for all currencies occurs within the hour but then quickly deteriorates. Within the hour adjustment is sufficiently quick to be considered efficient but the lack of full adjustment to fundamental value is not what would be predicted within an efficient market. There is no evidence for any of the currencies studied of a tendency to over react. There is also little difference in the speeds of adjustment between actively and less actively traded  currencies. There is however a definite difference in the speed at which currencies adjustment depending on whether they are free floating or managed exchange rates. Free floating rates adjust much quicker. Government intervention slows adjustment to fundamental value.

Mean reversion in stock prices: new evidence from panel unit root tests

Purpose – There are several studies that investigate evidence for mean reversion in stock prices. However, there is no consensus as to whether stock prices are mean reverting or random walk (unit root) processes. The goal of this paper is to re-examine mean reversion in stock prices.
Design/methodology/approach – The authors use five different panel unit root tests, namely the Im, Pesaran and Shin t-bar test statistic, the Levin and Lin test, the Im, Lee, and Tieslau Lagrangian multiplier test statistic, the seemingly unrelated regression test, and the multivariate augmented Dickey Fuller test advocated by Taylor and Sarno.
Findings – The main finding is that there is no mean reversion of stock prices, consistent with the efficient market hypothesis.
Research limitations/implications – One issue not considered by this study is the role of structural breaks. It may be the case that the efficient market hypothesis is contingent on structural breaks in stock prices. Future studies should model structural breaks.
Practical implications – The findings have implications for econometric modelling, in particular forecasting.
Originality/value – This paper adds to the scarce literature on the mean reverting property of stock prices based on panel data; thus, it should be useful for researchers.

Monetary models of exchange rates and the random walk

Three alternative monetary models of exchange rate are tested using data on the Italian lira - US doIIar exchange rate. II is shown that up to the early 1990s these economic models perform better than the random walk model in out-of-sample forecasts.

Do shocks to G7 stock prices have a permanent effect? : evidence from panel unit root tests with structural change

There is a plethora of studies that investigate evidence for the behaviour of stock prices using univariate techniques for unit roots. Whether or not stock prices are characterised by a unit root have implications for the efficient market hypothesis, which asserts that returns of a stock market are unpredictable from previous price changes. The extant literature has found mixed evidence on the integrational properties of stock prices. In this paper, for the first time, we provide evidence on the unit root hypothesis for G7 stock price indices using the Lagrangian multiplier panel unit root test that allows for structural breaks. Our main finding is that stock prices are stationary processes, inconsistent with the efficient market hypothesis.

The behaviour of US stock prices : evidence from a threshold autoregressive model

This paper investigates the behaviour of US stock prices using an unrestricted two-regime threshold autoregressive (TAR) model with an autoregressive unit root. The TAR model is applied to monthly stock price (NYSE Common Stocks) data for the US for the period 1964:06 to 2003:04. Amongst our main results, we find that the US stock price is a nonlinear series that is characterized by a unit root process, consistent with the efficient market hypothesis.

The purchasing of naming rights for sports stadiums : a harbinger of bad corporate governance or just bad timing?

The literature on corporate governance and the market’s delayed reaction to news events proliferated over the last two decades. This paper examines return patterns surrounding the event date for firms purchasing naming rights for North American sports stadiums. One argument appearing in the financial press is that such acquisitions are a harbinger of widespread corporate mismanagement and hubris at the highest levels of corporate governance. Purchases of stadium naming rights provide sidebenefits to executives such as “being in the limelight” and the use of supplementary corporate boxes. Thus, management has a strong incentive to undertake such investments even if their decision is not value enhancing to shareholders. The extent to which these agreements are associated with negative risk-adjusted returns is an empirical question, which this study addresses. On average, negative riskadjusted returns are observed over the three years following the event date, and these results are significant at standard levels of significance. The efficient market hypothesis suggests that these results are not due to a cause and effect relationship but represent data snooping or just bad timing.