In this paper, I explore a reform at the Oslo Stock Exchange to assess the causal effect of posttrade trader anonymity on stock liquidity and trading volume. Using a regression discontinuity approach, I find that anonymity leads to a reduction in bid‐ask spreads of 40% and an increase in trading volume of more than 50%. The increase in trading volume is accounted for largely by increased trading activity by institutional investors, while retail investors do not adjust their trading behavior in response to anonymity. The results suggest that posttrade anonymity positively affects standard measures of market quality.

中文翻译：

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股权匿名交易

在本文中，我将探索奥斯陆证券交易所的一项改革，以评估交易后交易者匿名对股票流动性和交易量的因果关系。使用回归不连续性方法，我发现匿名性导致买卖差价减少40％，交易量增加50％以上。交易量增加的主要原因是机构投资者的交易活动增加，而散户投资者并未根据匿名性调整其交易行为。结果表明，交易后匿名性对市场质量的标准度量产生积极影响。