Are herding transmissions in the gulf cooperation council stock markets regional or international?
Authors: Gabbori Dina , Awartani Basel , Maghyereh Aktham I. , Virk Nader 
Published: March 2021

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.