  A trite yet fundamental question in economics is: What causes large asset
price fluctuations? A tenfold rise in the price of GameStop equity, between the
22nd and 28th of January 2021, demonstrated that herding behaviour among retail
investors is an important contributing factor. This paper presents a
data-driven guide to the forum that started the hype -- WallStreetBets (WSB).
Our initial experiments decompose the forum using a large language topic model
and network tools. The topic model describes the evolution of the forum over
time and shows the persistence of certain topics (such as the market / S\&P500
discussion), and the sporadic interest in others, such as COVID or crude oil.
Network analysis allows us to decompose the landscape of retail investors into
clusters based on their posting and discussion habits; several large,
correlated asset discussion clusters emerge, surrounded by smaller, niche ones.
A second set of experiments assesses the impact that WSB discussions have had
on the market. We show that forum activity has a Granger-causal relationship
with the returns of several assets, some of which are now commonly classified
as `meme stocks', while others have gone under the radar. The paper extracts a
set of short-term trade signals from posts and long-term (monthly and weekly)
trade signals from forum dynamics, and considers their predictive power at
different time horizons. In addition to the analysis, the paper presents the
dataset, as well as an interactive dashboard, in order to promote further
research.

General Economics;Economics