In early 2021, the stock prices of GameStop, AMC, Nokia and BlackBerry experienced dramatic increases, triggered by short-squeeze operations that have been largely attributed to Reddit's retail investors. Here, we shed light on the extent and timing of Reddit users' influence on the GameStop short squeeze. Using statistical analysis tools with high temporal resolution, we find that increasing Reddit discussions anticipated high trading volumes. This effect emerged abruptly a few weeks before the event but waned once the community gained widespread visibility through Twitter. Meanwhile, the collective investment of the community quantified through posts of individual positions, closely mirrored the market capitalization of the stock. This evidence suggests a coordinated action of users in developing a shared financial strategy through social media--targeting GameStop first and other stocks afterward. Overall, our results provide novel insights into the role of Reddit users in the dynamics of the GameStop short squeeze.

翻译：2021年初，GameStop、AMC、诺基亚和黑莓的股价经历了剧烈上涨，这主要由轧空操作引发，而该操作被广泛归因于Reddit的散户投资者。本文揭示了Reddit用户在GameStop轧空事件中的影响程度与时机。通过采用具有高时间分辨率的统计分析工具，我们发现Reddit讨论的增加预示着高交易量的出现。这种效应在事件发生前几周突然显现，但在该社群通过Twitter获得广泛关注后逐渐减弱。同时，通过个人持仓帖量化的社群集体投资规模，与股票市值变化高度吻合。这些证据表明，用户通过社交媒体形成了协调行动，共同制定金融策略——最初针对GameStop，随后转向其他股票。总体而言，我们的研究为理解Reddit用户在GameStop轧空事件动态中的作用提供了新的见解。