Short-term share price overreaction : evidence from the Johannesburg Stock Exchange

The Overreaction Hypothesis and share price overreaction has been a widely researched phenomenon since the 1980s, although most work has focused on longer-term share return reversals. As an emerging market and part of the BRICS collective, South Africa provides an interesting investment environment within which to investigate this phenomenon. Limited research has been done in South Africa on share price overreaction, again nearly all focusing on the longer term. This dissertation examined short term overreaction (over 1 and 5-day periods) on the Johannesburg Stock Exchange (JSE) over the period July 2000 to June 2015. Furthermore, periods of financial crisis were isolated from the full sample period and tested separately, in order to assess whether periods of financial instability affect the magnitude of share price overreaction on the JSE. Whereas the common approach in this field is to investigate overreaction on a relative basis (for example by ranking share returns over a prior period and focusing on extreme relative performances), this thesis follows other literature that examines share return reversals following extreme one-day share price changes beyond absolute cut-off values (in this case ±5% and ±10%). The methodology considered an abnormal returns measure based on total return index values, and used a multivariate regression to test for one day and five day share return reversals. The effect of average prior returns, market volatility, company size, value, price-to-earnings and book-to-market ratios on abnormal returns were also considered. Lastly, a portfolio strategy based on one day and five day return reversals following large positive or negative one-day returns was investigated to test for usability as a possible trading strategy.

Grantor dc:publisher.institution

Department of Finance and Tax

Year dc:date.issued

2016

Author dc:creator

• Alur, Rushikesh

Advisor dc:contributor.advisor

• Toerien, Francois

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/11427/21748

OAI identifier oai:identifier

oai:open.uct.ac.za:11427/21748