[Over the past 40 years, the volatility of the average stock return has drastically outpaced total market volatility. Thus, idiosyncratic return volatility has dramatically increased. We estimate this increase to be 6% per year. Consistent with an efficient market, this result is mirrored by an increase in the idiosyncratic volatility of fundamental cash flows. We argue that these findings are attributable to the more intense economy-wide competition. Various cross-sectional and time-series tests support this idea. Economic competitiveness facilitates reinterpretation of the results from the cross-country R² literature, as well as the US idiosyncratic risk literature.]

[We investigate the trading of institutions immediately before the release of analysts' initial buy recommendations. We document abnormally high institutional trading volume and buying beginning five days before recommendations are publicly released. Abnormal buying is related to initiation characteristics that would require knowledge of the content of the report-such as the identity of the analyst and brokerage firm, and whether the recommendation is a strong buy. We confirm that institutions buying before the recommendation release earn abnormal profits. Our results are consistent with institutional traders receiving tips regarding the contents of forthcoming analysts' reports.]

I compare the return surrounding a sell-side analyst's initiation of coverage to the return surrounding a recommendation by an analyst who already covers the stock. The market responds more positively to analysts' initiations than to other recommendations. The incremental price impact of an initiation is 1.02% greater than the reaction to a recommendation by an analyst who already covers the stock. I examine whether the hypothesis that analyst coverage increases liquidity explains this incremental return. I find that liquidity improves after initiations, but that one must extend the liquidity hypothesis in order to fully explain the incremental price impact. Liquidity gains subsequent to analyst initiation depend on the analyst's recommendation. The more positive the initial recommendation, the greater the subsequent liquidity improvement. I also find that the initiation abnormal return correlates with the subsequent improvements in liquidity. Corporations should encourage analyst coverage to capture this liquidity benefit.

[Using a proprietary dataset of institutional investors' equity transactions, we document that institutional trading desks can sustain relative performance over adjacent periods.We find that trading-desk skill is positively correlated with the performance of the institution's traded portfolio, suggesting that institutions that invest resources in developing execution abilities also invest in generating superior investment ideas. Although some brokers can deliver better executions consistently over time, our analysis suggests that trading-desk skill is not limited to a selection of better brokers. We conclude that the trade implementation process is economically important and can contribute to relative portfolio performance.]

Twitter posts covering 1,082 firms from November 2008 to June 2011 reveal that sentiment in nonlocal Twitter posts is negatively related to future returns, and this negative relation is due to nonlocal posts favoring overpriced stocks, which earn lower subsequent returns. In contrast, local posts do not exhibit this failing. Since nonlocal posts dominate social media, this result highlights the danger of a naive reliance on social media sentiment. The nonlocal disadvantage is larger for firms without public news and firms with higher information asymmetry, suggesting that richer information constrains the exuberance of nonlocal investors.

Using unique data on brokerage-firm trading, I examine whether analysts' earnings forecasts and stock recommendations affect their brokerage firms' share of trading in the forecast stocks. I find that individual analyst's forecasts that differ from the consensus forecast generate significant brokerage-firm trading in the forecast stocks in the two weeks after the forecast release date, affirming that analysts' forecasts affect their brokers' commission revenue. However, I find no evidence that analysts' forecast errors—the difference between forecast earnings and actual earnings—increase brokerage-firm trading. This result suggests that analysts cannot generate trade for their employers simply by adding error to their forecasts. I find that buy recommendations generate relatively more trading, both buying and selling, through the analyst's brokerage firm. Collectively, these results suggest that analysts can generate higher trading commissions through their positive stock recommendations than by biasing their forecasts.

Over the past 40 years, the volatility of the average stock return has drastically outpaced total market volatility. Thus, idiosyncratic return volatility has dramatically increased. We estimate this increase to be 6% per year. Consistent with an efficient market, this result is mirrored by an increase in the idiosyncratic volatility of fundamental cash flows. We argue that these findings are attributable to the more intense economy-wide competition. Various cross-sectional and time-series tests support this idea. Economic competitiveness facilitates reinterpretation of the results from the cross-country R2 literature, as well as the US idiosyncratic risk literature.

[The institutional brokerage industry faces an ever-increasing pressure to lower trading costs, which has already driven down average commissions and shifted volume toward low-cost execution venues. However, traditional full-service brokers that bundle execution with services remain a force and their commissions are still considerably higher than the marginal cost of trade execution. We hypothesize that commissions constitute a convenient way of charging a prearranged fixed fee for long-term access to a broker's premium services. We derive testable predictions based on this hypothesis and test them on a large sample of institutional trades from 1999 to 2003. We find that institutions negotiate commissions infrequently, and thus commissions vary little with trade characteristics. Institutions also concentrate their order flow with a relatively small set of brokers, with smaller institutions concentrating their trading more than large institutions and paying higher per-share commissions. These results are stable over time, are consistent with our predictions, and cannot be explained by cost-minimization alone. Finally, we discuss the evolution of the institutional brokerage market within the proposed framework and make informal predictions about future developments in the industry.]

We use recent European restrictions to evaluate how traders substitute across available dark pools. Our findings suggest that restricting dark trading at the most prominent platform has a detrimental effect on dark trading activity. Annual dark trading in a restricted stock decreases by more than 50 % over the six-month restriction period. Consistent with investors’ sticky relationships with specific dark pools, our results suggest that substitution across dark pools is remarkably low. Despite the availability of alternative dark pools, traders are unwilling to trade elsewhere. Our study provides evidence that dark trading is not a market of exchanges, but rather a collection of independent silos. This fact has implications for the vulnerability of dark trading to the introduction of an HFT into the pool, and sharpens our understanding of how the pecking order theory of trading actually functions.