Smartphone Trading Technology, Investor Behavior, and Mutual Fund Performance.

Using proprietary individual-level trading data around a natural experiment—the release of a smartphone trading app by a large investment advisor—this study investigates how smartphone trading technology affects retail investor behavior and mutual fund performance. App adoption by retail investors leads to an increase in investor attention and trading volume. App adopters' flows become more sensitive to short-term fund returns and market sentiment, resulting in higher aggregate flow volume among adopters. The funds more exposed to the shock experience a greater decline in abnormal returns, likely attributable to higher fund flow volume and liquidity costs. As a result, both adopters and nonadopters experience a decline in their mutual fund investment returns. This paper was accepted by Lin William Cong, finance. Funding: The W. Edwards Deming Center and the Eugene Lang Entrepreneurship Center at Columbia University provided funding to support this research. Supplemental Material: The online appendices and data files are available at https://doi.org/10.1287/mnsc.2021.02099. [ABSTRACT FROM AUTHOR]