Investors herd when they follow the investment decisions of other market participants and ignore their own private information, causing asset valuations to deviate from their fundamentals. This paper examines herding in the South African equity market by examining the impact of investor fear on herding behavior, using a survivorship-bias free daily dataset of companies within the JSE All Share Index over the period: 3 May 2002 to 31 December 2019. Using the cross-sectional absolute deviation (CSAD), this study examines market-wide herding behavior over multiple sub-periods, which consists of before, during and after the global financial crisis of 2007/08. The results suggest no evidence of herding towards the market return; on the contrary there is evidence of ‘anti-herding' behaviour during periods of market stress. However, there is significant herding towards the domestic fear index, which becomes more pronounced during the crisis period. Furthermore, investor herd behaviour appears to be sensitive to spill-over effects from the US investor fear-gauge, suggesting interconnectedness with global financial markets. Therefore, these findings suggest that fear plays an important role in enforcing irrational behaviour.

Thesis (MComm)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: This study examines the role of cross-sectional return dispersion in portfolio management by examining two topics. To begin with, the study considers why return dispersion changes over time. Given the influence of return dispersion on active portfolio return opportunity, it is important for managers to understand why return dispersion changes over time. For a sample of South African listed shares over the period June 1996 to December 2011, univariate time-series analysis reveals significant serial correlation in return dispersion which may be modelled using ARMA (1, 1) and GARCH (1, 1) processes. Further analysis within a rational economic framework reveals that return dispersion is countercyclical to aggregate economic activity and related to both local and foreign economic uncertainty. The study then considers the relationship between return dispersion and the return to investment strategies. If substantial association between return dispersion and any investment strategy exists, then it is possible for managers and fund sponsors to augment an understanding of when active return opportunity is high with strategies for exploiting return opportunities. Continuing within the rational economic framework, the study uses Spearman‟s rank correlation coefficients to show a significant positive relationship between return dispersion and the value premium. In aggregate, these findings suggest that it is possible for South African investors to understand why return dispersion changes over time, as well as how to take advantage of changes in return dispersion. / AFRIKAANSE OPSOMMING: Hierdie studie ondersoek die rol van opbrengsverspreiding oor die kruissnit van „n mark in portefeuljebestuur deur twee onderwerpe te bestudeer. Eerstens bestudeer die studie hoekom opbrengsverspreiding oor tyd verander. Gegewe die invloed van opbrengsverspreiding op aktiewe beleggingsgeleentheid is dit belangrik vir bestuurders om te verstaan hoekom opbrengsverspreiding oor tyd verander. Vir „n steekproef van Suid Afrikaanse aandele oor die periode Julie 1996 tot Desember 2011 dui enkelvoudige tydreeks analise aan dat opbrengsverspreiding beduidende outokorrelasie het, waar die outokorrelasie beskryf word deur ARMA (1, 1) en GARCH (1, 1) prosesse. Verdere analise binne „n rasionele ekonomiese raamwerk dui daarop dat opbrengsverspreiding kontra-siklies aan makro-ekonomiese aktiwiteit is en verwant is aan beide plaaslike en buitelandse ekonomiese onsekerheid. Die studies ondersoek daarna die verhouding tussen opbrengsverspreiding en die opbrengs van beleggings strategieë. Indien daar „n noemenswaardige verhouding is tussen opbrengsverspreiding en enige beleggings strategie, dan kan bestuurders beter oordeel watter strategieë hoë opbrengste lewer wanneer beleggingsgeleenthede hoog is. Die studie hou binne „n rasionele ekonomiese raamwerk en gebruik Spearman se rang-orde korrelasie koeffisiënte om „n beduidende positiewe verwantskap tussen opbrengsverspreiding en die opbrengs van die waardepremie aan te dui. As „n geheel dui hierdie bevindinge daarop aan dat dit moontlik is vir Suid-Afrikaanse beleggers om te verstaan hoekom opbrengsverspreiding oor tyd verander asook hoe om voordeel uit die verwantskappe te trek.

In this paper, market participants’ tendency to form investor herds in the stocks listed on Nasdaq First North Growth Market of Sweden is examined for the period from 2018 to 2023. The models used in this study to detect herd behavior in stocks consist of two measures of dispersions, Cross-Sectional Standard Deviation of returns (CSSD) and Cross-Sectional Absolute Deviation of returns (CSAD), which were proposed by Christie and Huang (1995) and Chang, et al. (2000), respectively. An equally-weighted index consisting of all of the stocks that have traded on this market during the period is created and a quantitative analysis is conducted. Evidence showed absence of herd behavior when using both models, as well as when accounting for robustness tests consisting of small, mid-and large cap portfolios. Our results also support the prediction of rational asset pricing models, which suggest that stock return dispersions around the market returns increase during periods of market stress.