Herd on the Street

Kevin Lewis

September 19, 2022

Echo Chambers
Anthony Cookson, Joseph Engelberg & William Mullins
Review of Financial Studies, forthcoming


We find evidence of selective exposure to confirmatory information among 400,000 users on the investor social network StockTwits. Self-described bulls are five times more likely to follow a user with a bullish view of the same stock than are self-described bears. Consequently, bulls see 62 more bullish messages and 24 fewer bearish messages than bears do over the same 50-day period. These "echo chambers" exist even among professional investors and are strongest for investors who trade on their beliefs. Finally, beliefs formed in echo chambers are associated with lower ex post returns, more siloing of information, and more trading volume.

Sentimental Business Cycles
Andresa Lagerborg, Evi Pappa & Morten O. Ravn
Review of Economic Studies, forthcoming


We estimate the dynamic causal effects of consumer sentiment shocks in the US. We identify autonomous changes in survey evidence on consumer confidence using fatalities in mass shootings as an instrument. We find the instrument to be significant for an aggregate index of consumer expectations and also back up the identification scheme with micro evidence that exploits the geographical variation in mass shootings. Sentiment shocks have real macroeconomic effects. A negative sentiment shock is recessionary: It sets off a persistent decline in consumer confidence and induces a contraction in industrial production, private sector consumption, and in the labor market, while having less evident nominal effects. Finally, sentiment shocks explain a non-negligible part of the cyclical fluctuations in consumer confidence and real macroeconomic aggregates.

The 'Actual Retail Price' of Equity Trades
Christopher Schwarz et al.
University of California Working Paper, September 2022


We compare execution quality of six brokerage accounts across five brokers by generating a sample of 85,000 simultaneous market orders. Commission levels and payment for order flow (PFOF) differ across our accounts. We find that execution prices vary significantly across brokers: the mean account-level round-trip cost ranges from -0.07% to -0.46% excluding any commissions. The dispersion is due to off-exchange wholesalers systematically giving different execution prices for the same trades to different brokers. Across brokers, variation in PFOF cannot explain the large variation in price execution. We provide several suggestions for more informative disclosures on execution quality.

Competition for Attention in the ETF Space
Itzhak Ben-David et al.
Review of Financial Studies, forthcoming 


The interplay between investors' demand and providers' incentives has shaped the evolution of exchange-traded funds (ETFs). While early ETFs invested in broad-based indexes and therefore offered diversification at low cost, more recent products track niche portfolios and charge high fees. Strikingly, over their first 5 years, specialized ETFs lose about 30% (risk-adjusted). This underperformance cannot be explained by high fees or hedging demand. Rather, it is driven by the overvaluation of the underlying stocks at the time of the launch. Our results are consistent with providers catering to investors' extrapolative beliefs by issuing specialized ETFs that track attention-grabbing themes.

Cash to spend: IPO wealth and house prices
Barney Hartman-Glaser, Mark Thibodeau & Jiro Yoshida
Real Estate Economics, forthcoming


This study demonstrates the impact of initial public offerings (IPOs) on local house prices. Applying spatial difference-in-differences methods to IPOs in California from 1993 to 2017, we find house prices increase by 0.7% to 0.9% near an IPO firm's headquarters around filing and issuing dates. Upon lock-up expiration, price changes depend on post-issuance returns. Treating the San Francisco Bay as a commuting barrier, we identify sustained price increases after filings and temporary increases after issuing and lock-up expiration. We also confirm post-IPO price divergence between the treatment and synthetic control areas. Our findings indicate the effect of liquid wealth under mild financial constraints.

Running a mutual fund: Performance and trading behavior of runner managers
Arash Dayani & Sima Jannati
Journal of Empirical Finance, December 2022, Pages 43-62


This paper examines the relationship between the representation of marathon runners in a fund management team and its future performance. We find that funds with a larger proportion of runner managers have a higher level of risk-adjusted excess returns. We also find that these funds have a lower level of the disposition bias, deviate more from their benchmark portfolios, hold fewer stocks in their portfolios, and hold their stocks for a longer duration. Also, they tend to hold more stocks that are about to experience desirable earnings outcomes. Overall, the results suggest that personality traits that affects achievement in other dimensions of life may translate into fund management success.

Peer effects in equity research
Kenny Phua, Mandy Tham & Chishen Wei
Journal of Financial and Quantitative Analysis, forthcoming


We study the importance of peer effects among sell-side analysts who work at the same brokerage house, but cover different firms. By mapping the information network within each brokerage, we identify analysts who occupy central positions in their network. Central analysts incorporate more information from their coworkers and produce better research. Using shocks to network structures around brokerage mergers, we identify the influence of peer effects and the importance of industry expertise on analysts' performance. A portfolio strategy that exploits the forecast revisions of central analysts earns up to 24% per annum.

Risk-taking Begets Risk-taking: Evidence from Casino Openings and Investor Portfolios
Chi Liao
Financial Review, forthcoming


We provide evidence that casino openings can have spillover effects on an individual's portfolio risk-taking. Using investor-level brokerage data and the initial legalization and opening of commercial casinos in the United States as a quasi-natural experiment, we find that, after a casino opens in close geographical proximity to investors, those with a high propensity to gamble (PTG) increase their idiosyncratic portfolio risk by 12.88% relative to those unlikely to gamble. This effect lasts for approximately 3 months and does not affect systematic portfolio risk. These results suggest that increased access to gambling can temporarily increase portfolio risk-taking for those with a PTG.



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