本研究以企業現金持有之理論結合經理人股票選擇權是否使經理人有不同的投資決策。並提出在超額現金情境之下，經理人具有股票選擇權的風險誘因將會傾向透過執行併購的方式，增加非系統性風險的投資，並貢獻長遠的經濟利潤。本研究蒐集於 1992 年至 2014 年的 S&P1500 企業，根據是否具有超額現金將公司進行分組，並對選擇權誘因進行回歸分析。實證結果顯示具中有風險誘因的經理人在具有超額現金的公司中會有顯著更高的傾向執行併購，尤其當公司同時是屬於舊產業。此外當排除全額股票支付的併購與公開上市的被併公司後，投資人會給予顯著的正面反應。 / This study combines the cash holdings theory and executive stock options (ESOs), and investigates whether excess cash holdings could enlarge the risk incentive effect of ESOs on idiosyncratic-risk investments with positive NPV via mergers and acquisitions (M&As). By examining the Standard and Poor indexed 1500 firms from 1992 to 2014, we find that CEO with ESOs in cash-rich firm is significantly more likely to make M&As especially when the cash-rich firm is in old economy. In addition, investors give positive reaction when CEO with ESOs in cash-rich firm acquires a non-public target and doesn’t adopt the all-stock payment.