本研究主要探討新聞內容與股價間之關係，以臺灣三次油品事件爆發後一個月、共三個月之研究期間，探討21間食品類股，共1386筆樣本，在食品安全風波中所遭受的影響。與過往研究不同之處在於，本研究以文字探勘軟體分析後，將新聞內容依發言角色之不同分為五種類型：公司、政府、記者、民意、競爭對手。而後分別以Panel Data及事件分析法分析油品事件中，股價報酬率所受到的影響。
研究結果發現，競爭對手類之新聞對股價報酬最具有影響力，然而受到整體環境的改變而有不同影響，而新聞內容若為正面情緒，對股價報酬率有正面影響；若新聞內容為負面情緒，對股價報酬率則有負面影響。且若食品類股面臨多次負面事件，對股價報酬率的影響將比初次面臨負面事件強烈。

This study focuses on the relationship between news and the stock return of certain firms. The news content was classified by text mining program into five categories: firm, government, journalist, public opinion and trade rival. I used panel data and the event study method to analyze the effect of Taiwan’s three oil events on stock return.
The result shows that, it's the trade rival news that has the most influence on stock return; however, it's determined by the overall environment and context. If the news is positive, it has positive effect on the stock return, while if the news is negative, it's more likely for the stock return to go downward.

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