本研究探討企業的顧客集中度如何影響其股票流動性。本研究提出正反兩面假說以探討兩者之間的關係。此外,本研究也從客戶的議價能力、供應商的公司治理品質、與供應商與顧客的關係長度來探討顧客集中度與股票流動性兩者之間的影響機制。在處理內生性問題上,本研究也利用顧客產業的購併事件來當作顧客集中度的工具變數,並用兩階段最小平方法以解決內生性問題。此外,本研究也以顧客與供應商建立關係時點為事件,進行雙重差分分析以處理內生性問題。最後,本研究也提出穩健性檢驗以確認實證結果。 ;This research examines how a firm with concentrated customer base affects its stock liquidity. We propose two competing hypotheses to test this association. We also discover the channels for this association from the angles of customers’ bargaining power, suppliers’ corporate governance quality, and the length of customer-supplier relationships. To further deal with the endogeneity concerns, we use M&A waves in customers’ industries (downstream industry mergers) to instrument for customer concentration. We also follow Cen et al. (2017) and use relationship establishment as event study to conduct DID analysis to examine the impact of customer–supplier relationships on supplier’s stock liquidity. Lastly, we also propose a few robustness tests to verify our empirical results.