近年來各行各業飽受COVID-19疫情嚴重衝擊，使其成為最受關注的話題之一，亦為近日學術界所研究之關鍵事件。本研究以COVID-19為事件，檢測疫情前後期間從眾行為是否於臺灣股市發生，以臺灣788家上市公司為樣本，蒐集2018年01月30日至2022年01月30日之數據，並利用橫斷面絕對離散值模型檢測不同條件下之從眾行為訊號。研究結果顯示，從眾行為多在疫情前發生，且發生於市場較為低迷的情況下。因此，為防從眾行為對股市產生進一步的影響，投資者行為應被更嚴謹的觀察且監管。

COVID-19 has been used as a pivotal event for a wide range of academic researches. The severe impact caused by the pandemic through various industries and fields made COVID-19 one of the most important topics these years. This study takes COVID-19 as the incident, detecting whether herd behavior occurs before or during the period of pandemic in Taiwan stock market. By using samples of 788 listed companies in Taiwan, collecting data from 2018/01/30 to 2022/01/30, this study uses CSAD model to detect signals of herd behaviors under various conditions. Results show that herd behavior is more likely to occur before the pandemic and happens within the down markets. Consequently, a closer look of behaviors of investors should be taken in order to avoid further impact to the stock market by herd behavior.

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