Full Text Available

Note: Clicking the button above will open the full text document at the original institutional repository in a new window.

The impact of firm size and industry on director dealing profitability: evidence from the Johannesburg Stock Exchange

The purpose of this study is to investigate whether abnormal returns are earned on insider trading on the Johannesburg Stock Exchange (JSE). The study first tests the strong form of the Efficient Market Hypothesis by investigating whether abnormal returns are earned by directors purchasing or sellin...

Full description

Saved in:
Bibliographic Details
Main Author: Gallagher, Delano
Other Authors: Toerien, Francois
Format: Thesis
Language:English
Published: Department of Finance and Tax 2017
Subjects:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1867614531123937280
access_status_str Open Access
author Gallagher, Delano
author2 Toerien, Francois
author_browse Gallagher, Delano
Toerien, Francois
author_facet Toerien, Francois
Gallagher, Delano
author_sort Gallagher, Delano
collection Thesis
description The purpose of this study is to investigate whether abnormal returns are earned on insider trading on the Johannesburg Stock Exchange (JSE). The study first tests the strong form of the Efficient Market Hypothesis by investigating whether abnormal returns are earned by directors purchasing or selling their own firms' shares, and thereafter the semi-strong form of the Efficient Market Hypothesis by investigating the occurrence of abnormal returns earned by outsiders mimicking these director transactions once they are publically announced (which has to be within 48 hours). In addition, this study tests whether these abnormal returns are dependent on firm size, and secondly whether a firm's industry classification, as defined by the JSE, has an effect on the magnitude of abnormal returns earned by directors and outsiders mimicking these transactions. Event study methodology, in conjunction with the Market Model, is used to calculate the abnormal returns for a sample of 1,026 directors' trades made on the JSE between 2007 and 2012. The results indicate that directors in many of the subsamples tested earn statistically significant abnormal returns in the short term (defined as 20 days post the event date), when purchasing or selling shares in their own companies, although more so on sale trades. There is strong evidence of directors being able to time the market, and that outsiders can mimic directors' trades once these become public knowledge to also earn abnormal profits. These findings are inconsistent with both the strong and semi-strong forms of market efficiency. The study further finds a negative correlation between abnormal returns earned and firm size for both director share purchases and sales. This supports the theory that insiders in smaller companies, which are less exposed to market scrutiny than larger firms, possess greater private information than their counterparts in larger listed businesses. Finally, it is found that the highest insider abnormal returns were earned by director purchases in the Basic Materials and Oil & Gas sector, with the lowest abnormal returns earned in the Consumer Goods and Technology and Telecommunications sectors. The findings of this study have both theoretical implications in terms of the market efficiency of the JSE, as well as practical insights for investors looking for a profitable trading strategy based on director trades.
format Thesis
id oai:open.uct.ac.za:11427/22916
institution University of Cape Town (South Africa)
language eng
last_indexed 2026-06-10T12:53:31.280Z
license_str Not specified — see source repository
provenance_str_mv Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository
publishDate 2017
publishDateRange 2017
publishDateSort 2017
publisher Department of Finance and Tax
publisherStr Department of Finance and Tax
record_format dspace
source_str UCTD — University of Cape Town Open Access Repository
spelling oai:open.uct.ac.za:11427/22916 The impact of firm size and industry on director dealing profitability: evidence from the Johannesburg Stock Exchange Gallagher, Delano Toerien, Francois Financial Management The purpose of this study is to investigate whether abnormal returns are earned on insider trading on the Johannesburg Stock Exchange (JSE). The study first tests the strong form of the Efficient Market Hypothesis by investigating whether abnormal returns are earned by directors purchasing or selling their own firms' shares, and thereafter the semi-strong form of the Efficient Market Hypothesis by investigating the occurrence of abnormal returns earned by outsiders mimicking these director transactions once they are publically announced (which has to be within 48 hours). In addition, this study tests whether these abnormal returns are dependent on firm size, and secondly whether a firm's industry classification, as defined by the JSE, has an effect on the magnitude of abnormal returns earned by directors and outsiders mimicking these transactions. Event study methodology, in conjunction with the Market Model, is used to calculate the abnormal returns for a sample of 1,026 directors' trades made on the JSE between 2007 and 2012. The results indicate that directors in many of the subsamples tested earn statistically significant abnormal returns in the short term (defined as 20 days post the event date), when purchasing or selling shares in their own companies, although more so on sale trades. There is strong evidence of directors being able to time the market, and that outsiders can mimic directors' trades once these become public knowledge to also earn abnormal profits. These findings are inconsistent with both the strong and semi-strong forms of market efficiency. The study further finds a negative correlation between abnormal returns earned and firm size for both director share purchases and sales. This supports the theory that insiders in smaller companies, which are less exposed to market scrutiny than larger firms, possess greater private information than their counterparts in larger listed businesses. Finally, it is found that the highest insider abnormal returns were earned by director purchases in the Basic Materials and Oil & Gas sector, with the lowest abnormal returns earned in the Consumer Goods and Technology and Telecommunications sectors. The findings of this study have both theoretical implications in terms of the market efficiency of the JSE, as well as practical insights for investors looking for a profitable trading strategy based on director trades. 2017-01-23T07:55:43Z 2017-01-23T07:55:43Z 2016 Master Thesis Masters MCom http://hdl.handle.net/11427/22916 eng application/pdf Department of Finance and Tax Faculty of Commerce University of Cape Town
spellingShingle Financial Management
Gallagher, Delano
The impact of firm size and industry on director dealing profitability: evidence from the Johannesburg Stock Exchange
thesis_degree_str Master's
title The impact of firm size and industry on director dealing profitability: evidence from the Johannesburg Stock Exchange
title_full The impact of firm size and industry on director dealing profitability: evidence from the Johannesburg Stock Exchange
title_fullStr The impact of firm size and industry on director dealing profitability: evidence from the Johannesburg Stock Exchange
title_full_unstemmed The impact of firm size and industry on director dealing profitability: evidence from the Johannesburg Stock Exchange
title_short The impact of firm size and industry on director dealing profitability: evidence from the Johannesburg Stock Exchange
title_sort impact of firm size and industry on director dealing profitability evidence from the johannesburg stock exchange
topic Financial Management
url http://hdl.handle.net/11427/22916
work_keys_str_mv AT gallagherdelano theimpactoffirmsizeandindustryondirectordealingprofitabilityevidencefromthejohannesburgstockexchange
AT gallagherdelano impactoffirmsizeandindustryondirectordealingprofitabilityevidencefromthejohannesburgstockexchange