Aftermarket performance of health care and biopharmaceutical IPOs: Evidence from ASEAN countries

Abstract

We examine the evidence from the long-run abnormal returns using data for 76 health care and biopharmaceutical initial public offerings (IPOs) listed in a 29-year period between 1986 and 2014 in the Association of Southeast Asian Nations (ASEAN) countries such as Indonesia, Malaysia, Singapore, Thailand, the Philippines, Vietnam, Myanmar, and Laos. Based on the event-time approach, the 3-year stock returns of the IPOs are investigated using cumulative abnormal return (CAR) and buy-and-hold abnormal return (BHAR). As a robustness check, the calendar-time approach, related to the market model as well as Fama-French and Carhart models, was applied for verifying long-run abnormal returns. We found evidence that the health care IPOs overperform in the long-run, irrespective of the alternative benchmarks and methods. In addition, when we divide our sample into 5 groups by listing countries, our results show that the health care stock prices of the Singaporean firms behaved differently from those of most of the other firms in ASEAN. The Singaporean IPOs are characterized by a worse post-offering performance, whereas the IPOs of Malaysian and Thai health care companies performed better in the long-run.