Random Walks and Market Efficiency Tests: Evidence from Emerging Equity Markets

We use the multiple variance-ratio test of Chow and Denning (1993) to examine the stochastic properties of local currency- and US dollar-based equity returns in 15 emerging capital markets. The technique is based on the Studentized Maximum Modulus distribution and provides a multiple statistical comparison of variance-ratios, with control of the joint-test's size. We find that the random walk model is consistent with the dynamics of returns in most of the emerging markets analyzed, which contrasts many random walk test results documented with the use of single variance-ratio techniques. Further, a runs test suggests that most of the emerging markets are weak-form efficient. Overall, our results suggest that investors are unlikely to make systematic nonzero profit by using past information in many of the examined markets, thus, investors should predicate their investment strategies on the assumption of random walks. Additionally, our results suggest exchange rate matters in returns' dynamics determination for some of the emerging equity markets we analyzed.     

Testing the Random Walk Behavior and Efficiency of the Gulf Stock Markets

Inferences drawn from tests of market efficiency are rendered imprecise in the presence of infrequent trading. As the observed index in thinly traded markets may not represent the true underlying index value, there is a systematic bias toward rejecting the efficient market hypothesis. For the three emerging Gulf markets examined in this paper, correction for infrequent trading significantly alters the results of market efficiency and random walk tests. The Beveridge–Nelson (1981) decomposition of index returns is done to estimate the underlying index.     

A New Variance Ratio Test of Random Walk in Emerging Markets: A Revisit

Using a nonparametric variance ratio (VR) test, we revisit the empirical validity of the random walk hypothesis in eight emerging markets in the Middle East and North Africa (MENA). After correcting for measurement biases caused by thin and infrequent trading prevalent in nascent and small stock markets, we cannot reject the random walk hypothesis for the MENA markets. We conclude that a nonparametric VR test is appropriate for emerging stock markets, and argue that our findings can reconcile previously contradictory results regarding the efficiency of MENA markets.     

The Random Walk Hypothesis in the Emerging Indian Stock Market

This paper examines the random walk hypothesis in the emerging Indian stock market using daily data on individual stocks. The statistical evidence in this paper rejects the random walk hypothesis. The results suggest that daily returns earned by individual stocks and by an equally weighted portfolio show significant non–linear dependence and persistent volatility effects. The non–linear dependence takes the form of ARCH–type conditional heteroskedasticity and does not appear to be caused by nonstationarity of underlying economic variables. Though conditional volatility is time varying, it does not explain expected returns.     

Taper Tantrum and Emerging Equity Market Slumps

In the post-global financial crisis period, the central banks of the advanced economies pursued unconventional monetary policies, such as the United States (U.S.) Federal Reserve’s quantitative easing (QE). Those policies and their unwinding may significantly affect cross-border capital flows and thus destabilize the financial systems of emerging markets. For example, emerging markets experienced substantial financial instability during the taper tantrum triggered by U.S. Federal Reserve Chairman Ben Bernanke’s May 2013 announcement of the potential unwinding of QE. In this article, we examine the spillovers from the taper tantrum on emerging markets more rigorously by using econometric analysis to empirically assess the effect on equity markets in emerging markets. Our central finding that virtually all emerging-market equity markets were affected by the taper tantrum highlights the need for emerging-market authorities to remain vigilant about the effects of advanced-economy monetary policies on their financial stability.     

Brand Equity and Firm Risk: An Empirical Investigation in an Emerging Market

The aim of this article is to investigate the relationship between brand equity and firm risk in Turkey using a sample of 254 firm-year observations for the period 2009–2014. Our findings suggest that brand equity is an important determinant of equity risk in addition to conventional firm-specific variables. In particular, after controlling for firm-specific variables, the results reveal that firms with high brand equity experience lower volatility in stock returns. We also find that enhancing brand equity is an important tool for firms in reducing unsystematic and downside systematic risk in their stock prices. Our findings are robust to different valuation models of domestic and global investors as well as different methods of estimations. The results are encouraging for both marketing managers and investors, particularly those in emerging markets where stock price volatility is relatively higher than in developed markets.     

Securities Transaction Tax and Market Efficiency: Evidence from the Japanese Experience

This study examines the effect of transaction costs on the time series behavior of stock returns over a period surrounding the April 1989 changes in tax rates on securities transactions and capital gains in Japan. We find significant decreases in estimates of the first-order autocorrelation in returns for Japanese stocks listed in Japan, but no changes for Japanese stocks dually listed in the United States as American Depository Receipts (ADRs), which were not subject to the tax law change. We also find lower price basis between the ADRs and their underlying Japanese stocks. These results are consistent with the hypothesis that a reduction in transaction costs improves the efficiency of the price discovery process.

The Return Performance of Cubic Market Model: An Application to Emerging Markets

This article studies the performance of the high-order moment capital asset pricing model (CAPM) market models in emerging markets. We apply the cubic market model (4-moment CAPM) to 16 emerging market stock indices ranging from January 2010 to September 2015. Performance of the model is evaluated through the Fama and MacBeth’s two-step regression and through different corrections proposed in the literature, as well as generalized method of moments (GMM) estimation. According to Fama–MacBeth’s procedure, CAPM, the quadratic and cubic market models seem to be insignificant for the analyzed sample; however, the GMM estimation shows that quadratic model is valid for Indian, Polish, and Thai country indices, whereas cubic market model is accurate for Indian country index.     

Market Efficiency and the Returns to Simple Technical Trading Rules: New Evidence from U.S. Equity Market and Chinese Equity Markets

Numerous studies in the finance literature have investigated technical analysis to determine its validity as an investment tool. This study is an attempt to explore whether some forms of technical analysis can predict stock price movement and make excess profits based on certain trading rules in markets with different efficiency level. To avoid using arbitrarily selected 26 trading rules as did by Brock, Lakonishok and LeBaron (1992) and later by Bessembinder and Chan (1998), this paper examines predictive power and profitability of simple trading rules by expanding their universe of 26 rules to 412 rules. In order to find out the relationship between market efficiency and excess return by applying trading rules, we examine excess return over periods in U.S. markets and also compare the excess returns between U.S. market and Chinese markets. Our results found that there is no evidence at all supporting technical forecast power by these trading rules in U.S. equity index after 1975. During the 1990s break-even costs turned to be negative, –0.06%, even failing to beat a buy-holding strategyin U.S. equity market. In comparison, our results provide support for the technical strategies even in the presence of trading cost in Chinese stock markets.     

Testing Efficiency Across Markets: Evidence from the NCAA Basketball Betting Market

This study utilizes the National Collegiate Athletic Association basketball point spread betting market to investigate whether differences in information availability across markets result in different relative efficiencies of price formation within those markets. Using intra-conference games of various conferences as clearly defined markets, we show that these markets are efficient given the information available in those markets. However, we also show that regression error variances are significantly smaller (greater) for those conferences with greater (lesser) information availability. This evidence supports previous stock market research suggesting that differential fundamental information availability across stock markets results in differential departures from equilibrium values.     

Efficient Markets Hypothesis and the Emerging Capital Market in Sri Lanka: Evidence from the Colombo Stock Exchange – A Note

The behaviour of stock prices on the Colombo Stock Exchange (CSE) is examined with a view to determine its consistency with the weak form of the Efficient Markets Hypothesis (EMH). Runs, Autocorrelation and Cointegration tests are applied to daily, weekly and monthly CSE index data for the period of January 1991–November 1996. Results of Runs, Correlation and Cointegration tests overwhelmingly reject the serial independence hypothesis, leading to the conclusion that the behaviour of stock prices in the Colombo Stock Exchange is not consistent with the weak form of the Efficient Markets Hypothesis. Tests of the-day-of-the-week-effect, however, show that there is no evidence of such a phenomenon on the Colombo Stock Exchange stock prices. Results of the tests of the-month-of-the-year-effect lead to the conclusion that CSE prices do not display any month-specific behaviour.     

Market Efficiency, Thin Trading and Non-linear Behaviour: Evidence from an Emerging Market

Emerging markets efficiency has been widely investigated, with mixed results. However such evidence is only reliable if the methodology adopted accounts for the institutional features of the market. Unlike previous studies this paper corrects for thin trading and incorporates possible non-linear behaviour and regulatory changes. Using Istanbul Stock Exchange data we show that in its early years the exchange was characterised by non-linear behaviour and inefficient pricing. However, regulatory changes encouraged participation, improved information quality and led to prices impounding information more rapidly, suggesting markets become efficient with high trading volume, reliable information and an appropriate institutional framework.     

The Relationship Between Energy Commodity Prices and Electricity and Market Index Performances: Evidence from an Emerging Market

We investigate the effect of energy commodity price movements on market and electricity index returns in Turkey for the periods before, during, and after the year 2008. Although the Turkish economy is highly reliant on oil, we find that oil price does not lead either electricity or market indexes. This might be attributable to sluggish integration of financial markets in Turkey compared to developed markets. Natural gas price leads electricity index in the pre-2008 period. Its significance is reduced following the decline in natural gas usage in electricity production. This suggests that commodity dependence may be driving the link between commodity and asset prices in related sectors.     

A Market Efficiency Comparison of Islamic and Non-Islamic Stock Indices

This article examines the martingale difference hypothesis (MDH) and the random walk hypothesis (RWH) for nine conventional and nine Islamic stock indices: Asia-Pacific, Canadian, Developed Country, Emerging, European, Global, Japanese, UK, and United States. It investigates whether Islamic stock indices are more, less, or as efficient as their conventional counterparts. We test four sub-periods of bullish and bearish stock markets, together with the financial meltdown and its recovery, over the period 1997–2012. We use the Escanciano and Lobato’s (2009) automatic portmanteau test (AQ) and Deo’s (2000) test for the MDH. We also apply the automatic variance ratio test (AVR) developed by Choi (1999) and Kim (2009) for the RWH. Over the period from 1997 to 2012, we find that three conventional indices (Europe, Japan, and UK) are efficient, but that none of the Islamic indices are efficient in these markets. During the recent financial crisis, our results indicate slightly more efficiency for the Islamic indices than their conventional counterparts. Our study finds that overall the conventional indices are more efficient than their Islamic counterparts. Nevertheless, during periods of general downturns the Islamic indices have shown the same level of efficiency as their counterparts. Furthermore, it appears that during the last two sub-periods under study, the Islamic indices have moved toward efficiency, displaying the same level of efficiency as their counterparts.     

Market Reform and Efficiency: The Case of KOSPI200 Options

The Korean government and exchange have identified a need to regulate excessive speculative trading and to protect domestic individual investors from foreign and professional traders. As such, they have proposed an options market reform that requires higher levels of margin accounts for options trading and that increases the basic options multipliers in the KOSPI200 options market. This study examines how this market reform affects the price disagreement and adjustment behaviors of the index options market. Our analyses indicate that the efficiency and information quality of out-of-the-money options trades have increased since the reform took effect.     

Price-Formation Process of an Emerging Futures Market: Call Auction Versus Continuous Auction

This study assesses the market qualities of alternative price-formation processes for an emerging futures market—the Taiwan futures market. In 2002, the price formation process in the market changed during the period of trade between call auction and continuous auction. The performances of call auction and continuous auction are compared using intraday data. Empirical results show that the market is more liquid, and volatility is slightly lower, under continuous auction than under call auction. Also, there is robust evidence that continuous auction improves informative efficiency. The study suggests that for an emerging futures market like that of Taiwan, continuous auction offers a better trading environment for futures trading. In addition to demonstrating the virtue of continuous auction, this study also finds that the asymmetry in volatility is related to the price formation process. The asymmetry effect exists under continuous auction, but not under call auction.     

Arbitrage, Risk Premium, and Cointegration Tests of the Efficiency of Futures Markets

This article provides a new perspective on the efficiency of futures markets in a cointegration framework. Under the conventional risk premium hypothesis, if futures and spot prices are non-stationary, they must be cointegrated if futures markets are efficient. Alternatively, the cost-of-carry model implies that there should be a cointegration relationship among spot prices, futures prices and interest rates assuming all the series contain a unit root. Market efficiency further implies specific parameter restrictions under these two models. Using data on the futures markets for gold, silver, palladium and platinum, this article first establishes that interest rates, spot and futures prices are unit root non-stationary. The evidence on cointegration is somewhat mixed: the gold futures market is consistent with the cost-of-carry model, and the silver futures market satisfies the risk premium hypothesis, but the evidence for the other two markets is inconclusive.     

Assessing Selectivity and Market Timing Performance of Mutual Funds for an Emerging Market: The Case of Turkey

This paper derives and analyzes the selectivity and market timing performance of the mutual funds for the Turkish economy for the financial crisis period by employing high-frequency data. The determinants of these derived abilities are investigated within a regression analysis. The results suggest weak evidence about selection ability and some evidence about superior market timing quality. They also indicate that management fees are negatively correlated with the ability measure, which is quite surprising. Experience emerges as an important factor, especially for market timing ability.     

International Stock Market Efficiency and Integration: A Study of Eighteen Nations

This study examines the relationships among stock prices in eighteen national stock markets by using unit root and cointegration tests for the period 1961--92. All the markets were analyzed individually and collectively in regions to test for market efficiency. The results from unit root tests suggest that the world equity markets are weak-form efficient. The cointegration test results show that there are only a small number of significant cointegrating vectors over the last three decades. However, the number of significant cointegrating vectors increases after the October 1987 stock market crash, a result that is consistent with the contagion effect.     

股票价格均值回归理论研究综述

随机漫步理论认为股票的价格是不能预测的,许多实证检验的结果也支持了这一结论。但是,近年来均值回归理论对随机漫步理论提出了挑战。从长期来看,股票价格呈均值回归是必然的;均值回归具有不对称性;政府行为对股票的均值回归具有一定的影响。