We investigate the influence of oil market volatility and hand‐picked OPEC meetings data on herding tendency in the Saudi equity market. Our results show the presence of significant herding behaviour in the Saudi market; surprisingly this herding behaviour is independent of oil market volatility. Importantly, we find herding on and around the OPEC meeting days however this is only limited to a period of high global uncertainty that is, during the Global Financial Crisis period (GFC) of 2008–2010. However, when we filter out factor‐based herding in the Saudi equities, we also find persistent herding in the post GFC period. These results are consistent when we assess the impact of OPEC meetings using event windows of one to 5 days before and after the announcement. In consideration of the crucial role of OPEC in determining the oil prices, we explain our results of Saudi market herding on and around OPEC meeting days for the prior announcement ambiguity and corrections before, on and after the announcements on global supply. Our results show that this tendency has originated during the GFC, has persisted in the post‐GFC in the Saudi equities and surprisingly, is largely found absent in the periods when the Saudi equity market witnessed bullish market conditions. Our results are robust after accounting for common factor return variations in equity returns, the unconditional and conditional estimates of the volatility in oil prices and several event windows around OPEC meeting days.

Using data from Saudi Arabia, a strictly religious society, we examine how Islamic events (i.e., Ramadan, Eid‐ul‐Fitr, Eid‐ul‐Adha and Ashoura) moderate the impact of social mood (positive and negative) on herding in the stock market. We use the cross‐sectional absolute deviation (CSAD) of returns and find that investors' mood during Islamic events of Eid‐ul‐Fitr, Eid‐ul‐Adha and Ashoura significantly affects herding behaviour in the market. Our results, however, contrast with existing evidence of herding in the month of Ramadan. Overall, results are robust after controlling for market conditions (i.e., domestic and US market returns, liquidity, sentiments, and oil price volatility) and crisis events (i.e., global financial crisis and Arab Spring). Though most prior research investigates the impact of individual Islamic events on stocks as seasonal anomalies, our study contributes by jointly exploring how four key Islamic events, associated with contrasting moods, induce diverse herding patterns in the Saudi stock market.

PurposeThe authors aim to assess whether herding in GCC stock markets is more responsive to global dynamics than its response to regional developments. To do so, they use the largest equity market in the region which is Saudi Arabia as the benchmark, and then they examine if herding crosses from this large regional market to the rest of equities in the neighboring markets during various time periods. To compare the importance of global influences on herding, the authors investigate and compare the impact of the information flow from the US equity market on the herding of equities in the GCC markets.Design/methodology/approachTo investigate herding in GCC markets the authors use the relationship between the squared market return and the cross-section absolute deviation that does not covary with market styles and/or fundamentals. In order to do that we follow Galariotis et al. (2015) and account for four styles: market-oriented, small-cap, value and momentum. As these factors have been shown to be associated with the economic fundamentals, filtering the covariance of deviation with these factors is expected to remove the style and the fundamental herding influence from the value of the dispersion.FindingsThe results show significant herding behavior that persists across various independent periods. This evidence stands even when the authors control for the well- known factor structures in stock returns. Importantly, the authors find that the few herding crossovers that occurred during the sample period are more likely to originate from the Saudi market rather than from the US. Therefore, the authors conclude that behavioral inefficiencies in the GCC equity markets are likely to be regional and that the sentiment-based trading in the US has essentially a minimal role to play.Practical implicationsThe empirical findings are useful for policymakers who aim at preventing market manipulation in order to preserve the integrity of financial markets. Policymakers in the GCC should disclose more information to aid investors so they do not rely on other investors' trades. The portfolio managers should be aware that the correlation of GCC equities can be higher in the short term due to common market herding in these countries. As the US market does not play an important role in triggering behavioral irrationalities in these markets, investing in GCC equities is a good hedge in a US portfolio. Finally, the results have also important implications for active funds that aim to exploit short-term trending in markets in order to enhance performance.Originality/valueThe authors’ contribution in this paper is to investigate herding in GCC markets by using the relationship between the squared market return and the cross-section absolute deviation that does not covary with market styles and/or fundamentals. Another contribution of our paper is to investigate any cross herding from the Saudi market to the rest of the markets in the area. The previous literature on GCC equity market herding is silent on this issue and it is typically restricted to the level of the single market.