Companies adopting capital reduction to offset losses generally cause negative effects in the market, thereby leading stock price falls. To examine whether investors react differently to such companies exhibiting varying characteristics, this study adopted the BCG matrix by categorizing sample companies as “Dogs,” “Stars,” “Problem Marks,” and “Cash Cows,” employing an event study method to assess the abnormal returns of each sample company that announced capital reduction; this empirical study thereby serves as a reference to management and investors regarding policymaking. The samples were listed and over-the-counter companies that engaged in capital reduction in 2004–2014. The results of this empirical study indicated that the market had various reactions to the sample companies with differing characteristics. Among these samples, “Dogs “and “Stars” caused negative reactions,” Cash Cows” caused positive reactions, and” Problem Marks” caused shifts from negative to positive reactions.