HKS Affiliated Authors


Insider Trading and Stock Splits. Richard Zeckhauser, July 30, 2012, Paper. "Stock splits have long presented a puzzle in finance. Unresolved questions are why do firms undertake them, and why do they offer abnormal returns both before and after the announcement date? Conventional explanations focus on making stocks more liquid and signaling firm prospects. However, abnormal returns, particularly before the announcement date, should raise strong suspicions of insider trading. We examined 718 split events in the emerging stock market of Vietnam and found evidence indicating illegal insider trading in stock splits by firms more vulnerable..." Link