Pilar Corredor

Does herding affect volatility? Implications for the Spanish stock market

According to rational expectation models, uninformed or liquidity trading make market price volatility rise. This paper sets out to analyse the impact of herding, which may be interpreted as one of the components of uninformed trading, on the volatility of the Spanish stock market. Herding is examined at the intraday level, considered the most reliable sampling frequency for detecting this type of investor behavior, and measured using the Patterson and Sharma (Working Paper, University of Michigan–Dearborn, 2006) herding intensity measure. Different volatility measures (historical, realized and implied) are employed. The results confirm that herding has a direct linear impact on volatility for all of the volatility measures considered, although the corresponding intensity is not always the same. In fact, herding variables seem to be useful in volatility forecasting and therefore in decision making when volatility is considered a key factor.

Forecasting volatility in the Spanish option market

The performance of several alternative forecasts for the Ibex-35 index options market data is compared and a test for market efficiency of the Spanish Option Market with respect to volatility forecasts provided. The forecasts include time series, implied volatilities and composite specifications using both parametric and nonparametric ways. It is found that the choice of the best model depends on the error measurement that depends on the ultimate purpose of the forecasting procedure. Also the results generated from an ex ante arbitrage strategy are not different from zero at conventional significance levels once the transaction costs are taken into account. This result supports the hypothesis of the market efficiency of the Spanish Option Market.

Bad news and Dow Jones make the Spanish stocks go round

This paper is a data-based attempt to analyse what kind of information basically affects close-to-open returns, open-to-close returns, volatility and volume in actively traded individual securities on the Spanish stock market. Specifically, we are interested in detecting how these variables react to specific pieces of news considered as exogenous information. However, as volume itself could be interpreted as a proxy of the information flow, we first apply the linear and nonlinear Granger causality tests from volume to return and to volatility. We do not find evidence supporting this latter hypothesis. Furthermore, we only find significant evidence of linear causality from volume to volatility. The other major finding is that both bad news and the Dow Jones play a significant informational role in explaining price changes and volatility. As a consequence of these findings, we also test the residual role of volume as a proxy for noise/liquidity trading after filtering for news, although we do not find evidence in favour of this argument.

Market Sentiment: A Key Factor of Investors’ Imitative Behaviour

The aim of this paper is to explore herding behaviour among investors to determine its rational and emotional component factors and identify relationships among them. We apply causality tests to evaluate the impact of return and market sentiment on herding intensity. The herding intensity is quantified using the measure developed by Patterson and Sharma (2006). The research was conducted during the period 1997–2003 in the Spanish stock market, where the presence of herding has been confirmed. The results reveal that the herding intensity depends on past returns and sentiment or subjective assessments and confirm the presence of both a rational and an emotional factor.

Is bad news cause of asymmetric volatility response? A note

This article uses a direct test of the impact of economic news on stock volatility. The main interest is to test whether the asymmetric response of volatility can be due to the effect of bad news. To do this, this study takes items of news into account as exogenous variables. The analysis is divided into two stages, each of which uses different items of news as exogenous variables additional to the information provided by the residuals. The first stage uses more exhaustively classified information whereas the second considers daily information as a global sign. This study finds that bad news is responsible for most of the observed asymmetric behaviour of variance. Further, this study detects that the GJR model adequately captures the impact of bad news when traders are not ready to carry out a time-consuming analysis of the information.

Detecting Intentional Herding: What Lies Beneath Intraday Data in the Spanish Stock Market

This paper examines the intentional herd behaviour of market participants, using Lis test to compare the probability distributions of the scaled cross-sectional deviation in returns in the intraday market with the cross-sectional deviation in returns in an ‘artificially created’ market free of intentional herding effects. The analysis is carried out for both the overall market and a sample of the most representative stocks. In addition, a bootstrap procedure is applied in order to gain a deeper understanding of the differences across the distributions under study. The results show that the Spanish market exhibits a significant intraday herding effect that is not detected using other traditional herding measures when familiar and heavily traded stocks are analysed. Furthermore, it is suggested that intentional herding is likely to be better revealed using intraday data, and that the use of a lower frequency data may obscure results revealing imitative behaviour in the market.

Information Spillovers between Derivative Markets with Differences in Transaction Costs and Liquidity

In line with the transactions cost theory, this article shows that the futures market with its higher liquidity and lower transactions costs, leads the options market in the price discovery process. Liquidity and transaction costs are also shown to play a key role in market sensitivity to information, since the futures market s response to shocks is quicker, which means that it receives higher volatility spillovers than does the options market.

Does Informed Trading Occur in the Options Market? Some Revealing Clues

This paper analyses the relationship between proxy variables for informed trading in the options market and a set of exogenous news variables. The aim was to test directly for the presence or absence of informed trading in the options market and for the possible impact of this trading on underlying asset prices. Our findings reveal that potential informed trading in options markets is channelled basically through out-of-the-money options, except for volatility trading which mainly involves at-the-money options because of their liquidity. In both cases, we have found evidence in favour of investors’ strategic fragmentation of transactions into intermediate size trades (stealth trading). Finally, it is shown that lack of consensus among agents also generates increased trading, particularly in out-of-the-money and at-the-money options.

Value of Analysts’ Consensus Recommendations and Investor Sentiment

This paper studies the effect of investor sentiment on analysts’ consensus recommendations. Our results show that the optimistic bias of analysts in the issuing of recommendations is affected by investor sentiment: the greater the investor sentiment, the more optimistically biased the analysts’ consensus recommendations. This bias is larger in stocks whose characteristics make them hard to value or to arbitrage. We also show that investor sentiment can help in the design of profitable strategies, particularly when taking the short position in portfolios with high sentiment sensitivity stocks.

Transaction costs, arbitrage, and volatility spillover: a note

Abstract In this paper, we analyze the effect of the reduction of transaction costs on the correlation between the spot index and the index futures returns and on the linkage in the second moments of both markets. Using a bivariate Glosten–Jagannathan–Runkle (GJR) process, that takes into account cross-market interactions, we find that the reduction of the width of the nonarbitrage band leads to a significant increase in the contemporaneous correlation and to a significant increase in the volatility spillovers between the two markets.