'COVID-19 and Investor Behavior'




This project investigates the impact of a pandemic on investors’ trading activities. We show that investors significantly increase their trading activities as the pandemic unfolds, both at the extensive and at the intensive margin. We observe that the number of investors who first open an account with the broker increases, while at the same time established investors increase their average trading activities. A 100% increase in COVID-19 cases is associated with a ~14% increase in the average weekly trading intensity. The increase in trading is especially pronounced for male and older investors and affects stock and index trading. The increase is largest during the period from February 23rd to March 22nd. CFD trading and the trading of crypto currencies are less affected. Following the 9.99%-percentage drop of the Dow Jones on March 12th, investors significantly reduce the usage of leverage across all asset classes, except cryptocurrencies. (Working Paper, Media coverage: Bild)


'Attention Triggers and Retail Investors' Trading Behavior'



(c) Florian Stolle

This project investigates the impact of individual attention on investor risk-taking and short selling. We analyze a large, novel sample of trading records from a European brokerage service that allows its customers to trade contracts-for-differences (CFD), and sends standardized push messages on recent stock performance to its client investors. The advantage of this sample is that it allows us to isolate the "push" messages as individual attention triggers, which we can directly link to the same individuals' risk-taking. A particular advantage of CFD trading is that it allows investors to make use of leverage, which provides us a pure measure of investors' willingness to take risks that is independent of the decision to purchase a particular stock, and short selling. Leverage is a major catalyst of speculative trading, as it increases the scope of extreme returns, and enables investors to take larger positions than what they can afford with their own capital. Short selling provides important flexibility for investors to adjust their portfolio to reflect their changing views. We show that investors execute attention-driven trades with higher leverage, compared to their other trades, as well as those of other investors who are not alerted by attention triggers. Attention traders also take short positions more frequently.  (Working Paper)

In a second paper, we also investigate the impact of attention on portfolio diversification. We show that the effect of push messages on investors' portfolios critically depends on whether investors hold a stock in their portfolio at the time of the push message. Investors who do not hold the stock in their portfolio when receiving the message hold better diversified portfolios 24 hours after the push message, while investors who hold the stock in their portfolio at the time of the message decrease their diversification. Hence, we highlight two opposing channels for the impact of attention triggers on risk-taking. Whereas (i) attention triggers induce investors to take more idiosyncratic risk, (ii) these triggers also stimulate portfolio diversification.

Amongst others, our project complements studies that explore the reason behind retail investors' mistakes. Hence, the results of our project have several practical implications for investment management. Specifically, it allows investors and investment advisors to understand the impact of attention on individuals' trading and portfolios. Using this knowledge, advisors can provide guidance to their customers to improve their trading outcomes. For example, our results suggest that purposefully sent push messages may help investors overcome the common mistake of holding under-diversified portfolios. As such, the use of push messages may have stronger effects on investors' portfolios than other types of financial education.

Financial support by the Fritz Thyssen Stiftung (Az. is gratefully acknowledged.



'Social Interactions and (Financial) Decision-Making'



(c) Florian Stolle

This project studies the impact of social interactions on investors' financial decision-making and risk-taking. In particular, we study preferences for dependencies between payoffs for own prospects in relation to payoffs of peers' prospects and the implications of such dependencies for investors' risk-taking.

Financial support by the Deutsche Forschungsgemeinschaft (project number 434732045) is gratefully acknowledged.