Millions of hidden U.S. trades were revealed for the first time last December when a new SEC rule took effect. For the first time, odd-lot trades—those with fewer than 100 shares—appeared on the consolidated order book. That means information on those deals is available to everyone, not just investment banks and sophisticated traders.
Sources: “What’s Not There: Odd-Lots and Market Data” (Journal of Finance, 2014) by Maureen O’Hara, Chen Yao and Mao Ye; Mark Yamada; SEC; Consolidated Tape Association.
*Data not yet available for trading since the SEC’s latest rule took effect.
Jessica Bruno is a Toronto-based financial writer.