Date of Award


Degree Type

Doctoral Dissertation

Degree Name

Doctor of Business Administration (DBA)


Jack Welch College of Business


Corrected version uploaded June 25, 2019.

Dissertation Supervisor

Dr. Kwamie Dunbar

Committee Member

Dr. Karen Cascini

Committee Member

Dr. Jing Jiang


This event study examines the short-run effect of stock buyback announcements on stock price and credit default swaps (CDS) exclusively for mega capitalization S&P 100 companies. The research sample consists of 53 S&P 100 companies and includes 133 buyback announcement events occurring between September 2011 and May 2018. The study utilizes the market model to estimate expected returns and to compute abnormal returns (AR) for equity and abnormal change (AC) in CDS. Based on an initial analysis, it’s determined that there is a statistically significant AR and cumulative abnormal return (CAR) for stock price, and a significant AC in CDS, on a buyback announcement date. Regarding share price, AR and CAR were further tested for significance against an array of firm-specific control variables, for the event date and subsequent days. Additionally, robustness tests were employed. All results demonstrate that stock buyback announcements are significantly correlated with AR in stock price. As for CDS, an identical research process was conducted. However, while there is also preliminary evidence that stock buyback announcements impact CDS on the event date, the results are less conclusive when assessing the AC and CAC against control variables. Throughout the paper, all data and research findings will be discussed, along with a comprehensive literature review. Finally, conclusions will be drawn and interpretations are offered.

Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.



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