Causal role, timing, and extent of Reddit’s influence on meme-stock price surges

Determine how, when, and to what extent Reddit users played a causal role in driving the price increases of GameStop (GME), AMC Entertainment (AMC), Nokia (NOK), and BlackBerry (BB) during early 2021.

Background

In early 2021, several stocks (GME, AMC, NOK, BB) experienced dramatic price surges often associated with short squeeze dynamics and widely attributed to retail investor activity on Reddit. Despite widespread narratives, the precise causal influence, temporal dynamics, and magnitude of Reddit’s impact remained unsettled.

The paper addresses this uncertainty by integrating social media signals and high-resolution trading data, aiming to disentangle Reddit’s causal effects, their onset, and strength across platforms and stocks.