Algorithmic trading and block ownership initiation: An information perspective

This paper examines the impact of algorithmic trading (AT) on investors' incentives to initiate block ownership in U.S. public companies. We find that a one standard deviation change in AT activity reduces the block ownership initiation likelihood by 3.5%. Using the SEC's randomised tick size pilot experiment in 2016 as a negative shock to AT, we show that the effect of AT on block ownership initiation is causal. Further evidence supports the information-hindering explanation that AT discourages sophisticated investors from acquiring information, which results in a decrease in block ownership initiation. We find that the effect of AT is more pronounced among information-sensitive investors and that institutional investors reduce their information gathering activities in AT-targeted stocks. Additional tests exploring information-based trading behaviour in the presence of AT provide strong evidence to support the explanation of information-hindering, and our results hold across a battery of robustness tests.