Tokyo Stock Exchange Trading Network (ToSTNeT) is a unique market in Japan in which firms can repurchase their shares during off-auction hours at a fixed price within a very short timeframe. In this study, we uncover a drawback in ToSTNeT which appears to have been exploited by managers of the repurchasing firms to favour certain sellers who have close economic ties with the firms. Further investigations reveal that it is impractical for retail investors to sell their shares on ToSTNeT. Our study proposes recommendations of regulatory and policy changes for the Tokyo Stock Exchange that may help tighten the loophole in ToSTNeT and safeguard the integrity of share repurchases in Japan.

东京证券交易所交易网络 (ToSTNeT) 是日本独特的市场，公司可以在非拍卖时间在很短的时间内以固定价格回购其股票。在这项研究中，我们发现了 ToSTNeT 的一个缺点，它似乎已被回购公司的经理利用，以偏袒与公司有密切经济联系的某些卖家。进一步调查显示，散户投资者在 ToSTNeT 上出售其股票是不切实际的。我们的研究为东京证券交易所提出了监管和政策变化的建议，这可能有助于弥补 ToSTNeT 的漏洞并维护日本股票回购的完整性。