We show that retail traders in 2019-2020 incur transaction costs an order of magnitude smaller than those during the Barber and Odean (2000) sample and spreads 35% to 60% smaller than comparable institutional spreads. Moreover, retail effective spreads changed only trivially relative to...

Using rule 605 reports from major market makers that receive retail order flow, we examine the impact of zero-commission trades on order execution quality. We find that the effective spread for marketable orders between 100 and 499 shares marginally decreased following the zero-commission cut....

We analyze the role of retail investors in stock pricing using a database uniquely suited for this purpose. The data allow us to address selection bias concerns and to separately examine aggressive (market) and passive (limit) orders. Both aggressive and passive net buying positively predict...