本研究探討管理者在制定股票回購決策時，是否會納入股價中所蘊含的私人資訊。本文以Tobin’s Q 作為基於股價的訊號，檢驗股票回購對股價的敏感度是否會隨股價資訊性（Stock Price Informativeness, SPI）提高而增強。並進一步分析，較高的股價資訊性是否降低企業對內部現金流訊號的依賴，以及此學習效果是否在大型企業中更為顯著。
基於1994年至2024年間美國上市公司之面板資料，實證結果支持上述假說：（i）當股價資訊性較高時，股票回購與Tobin’s Q的負向關係顯著更強，顯示管理者會從股價中學習市場所揭示的新投資機會資訊，並據以調整股票回購決策；（ii）股價資訊性的提升亦降低企業對自由現金流訊號的依賴；（iii）大型企業的管理者學習效果更為明顯。主要結論經由Fama–MacBeth橫斷面估計與Logit模型之檢驗下仍具穩健性。
本研究的主要貢獻在於將管理者學習理論文獻延伸至股票回購決策，並提供一個以資訊條件為基礎的分配與投資機會關係之觀點。

This study examines whether managers incorporate private information from stock prices when setting share repurchase policy. Using Tobin’s Q as the price-based signal, we test whether higher stock price informativeness (SPI) strengthens the sensitivity of share repurchases to stock price. We also assess whether SPI reduces reliance on internal cash flow signal and whether the learning effect is stronger for larger firms.
Panel evidence for U.S. public firms from 1994 to 2024 supports these predictions: (i) the negative relation between repurchases and Tobin’s Q is significantly stronger when SPI is high, demonstrating that managers learn from stock prices about newly revealed investment opportunities and adjust share repurchase decisions accordingly; (ii) managers place less weight on free cash flow in price information-rich settings; (iii) and the moderating role of SPI is more pronounced among large firms. Main results are robust to standard specification checks, including Fama–MacBeth estimates and a logit specification for repurchase incidence.
The primary contribution of this study is to extend the managerial learning literature to share repurchase decisions and to provide an information-conditioned view of the relation between payout and investment opportunities.

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