We demonstrate that off-exchange (wholesaler) executions provide significant cost savings to retail investors. Wholesaler concentration has raised regulatory concerns; however, we show that the largest wholesalers offer the lowest costs due to economies of scale. The entry of a new large wholesaler reduces incumbent scale economies, resulting in higher execution costs. Most retail brokers route to multiple wholesalers and actively monitor their performance, rewarding those offering lower execution costs with more volume. While retail investors benefit from the current landscape across all stocks, those trading small stocks benefit the most.

We document significant increases in short positions on days when company insiders sell their firms’ shares. Short selling increases before insider sales are publicly reported and often before insiders finish selling. Furthermore, the magnitude of short selling activity is consistent with short sellers’ knowledge of the insider’s rank (e.g., CEO, CFO, or a lower-ranked manager) and with knowledge of the unobservable size of the insider’s trading position. We show that short sellers’ superior timing is consistent with (i) monitoring of order flow and (ii) obtaining price-relevant information from brokerages that execute insider sales. Some of our results extend to insider purchases.

Modern markets are characterized by speed differentials, with some traders being fractions of a second faster than others. Theoretical models suggest that such differentials may have both positive and negative effects on liquidity and gains from trade. We examine these effects by studying a series of exogenous weather episodes that temporarily remove the speed advantages of the fastest traders by disrupting their microwave networks. The disruptions are associated with lower adverse selection and lower trading costs. In additional analysis, we show that the long‐term removal of speed differentials results in similar effects and also increases gains from trade.

Consistent with prior literature, we find that average relative effective spreads are higher for venues that pay for order flow (PFOF) than for venues utilizing the maker-taker (MT) model. This relation becomes more nuanced when liquidity fees are incorporated into liquidity cost measures. For the majority of options, PFOF venues offer lower average liquidity costs net of taker fees. Net liquidity costs for the high-priced options, however, are lower for MT venues. Overall, our results suggest that the inclusion of fees and rebates can rationalize the routing of most, but not all, marketable orders to PFOF venues.

Researchers are often interested in modeling binary decisions made by firms (e.g., the yes or no decisions to split the shares, initiate a dividend, or acquire another firm) as functions of economy-wide variables (common factors). Although factor models for continuous dependent variables are used widely, the toolkit of a financial researcher does not contain a generally accepted methodology that allows estimating factor models for binary dependent variables. In this paper, we study such a methodology. Using simulations, we identify data characteristics that allow for reliable estimates of factor parameters and conclude that the methodology is appropriate for the panel datasets of the type often used in finance. As an illustration, we use the methodology to address a currently debated issue of common factors in firms’ decisions to split their shares.

We test the split signaling hypothesis by examining the reaction of sophisticated investors to stock split announcements. Return-based tests of signaling used in earlier studies produce conflicting results and have been criticized as unreliable. We overcome this issue by focusing on the long-term post-split behavior of short sellers, who are widely regarded as sophisticated investors. Upon controlling for alternative hypotheses and conventional short selling determinants, we find a substantial reduction in short interest in reaction to split announcements. Furthermore, consistent with signaling, the degree of the reduction is positively related to signal strength and to the splitter's level of information asymmetry. Overall, our results are consistent with the view that firms use stock splits to relay positive value-relevant signals.