本研究以2014至2024年間臺灣上市電子業公司為樣本，探討ETF持股是否影響企業投資效率，並進一步評估對績效的影響。採用Richardson (2006)模型衡量投資效率，並以ETF持有家數與類型為主要自變數，控制公司特徵與年度效果，使用Tobin’s Q作為績效指標，研究結果顯示：（1）ETF持股與投資效率偏離程度呈正相關，顯示其對企業投資行為具影響力；（2）ETF持股顯著提高過度投資行為，對投資不足無顯著影響；（3）成長型ETF對過度投資有更顯著正向關聯；（4）過度投資與Tobin’s Q呈正相關，市場可能視其為成長性訊號；（5）過度投資在ETF持股與績效間具部分中介效果。研究補足充ETF影響企業決策之文獻，並提供企業決策者在公司被ETF持股時進行資源配置的參考依據。;High-tech firms rely heavily on R&D and capital expenditures to achieve sustainable growth. Due to the difficulty in reflecting growth potential through financial statements, these firms are more sensitive to market signals and liquidity. As Exchange-Traded Funds (ETFs) grow in market influence, they have become an important external capital source. However, how ETF ownership affects corporate investment efficiency and performance remains underexplored. Using data from Taiwan-listed electronics firms from 2014 to 2024, this study examines whether ETF ownership influences investment efficiency and, in turn, firm performance. Investment efficiency is measured using the Richardson (2006) model, where deviations from expected investment indicate over- or under-investment. The main independent variable is the number of ETF shareholders, with further classification by ETF type. Tobin’s Q measures long-term performance, and firm- and year-level controls are included. Results show that: (1) more ETF shareholders are associated with greater deviations in investment efficiency; (2) ETF ownership significantly increases overinvestment, with no effect on underinvestment; (3) growth ETFs have the strongest link to overinvestment; (4) overinvestment is positively related to Tobin’s Q; and (5) overinvestment partially mediates the effect of ETF ownership on firm performance. This study fills a gap in the literature by highlighting how ETF ownership can influence resource allocation and performance, particularly in high-tech industries, and offers insights for corporate decision-making under increasing ETF presence.
