A war between individual investors and Wall Street institutions that occurred in January 2021 has attracted attention worldwide. There were many participants in this event, and the causality behind that was also complex. Due to the COVID-19, people work from home, so social media has become the main battlefield of GameStop events, especially Reddit's subreddit: r/WallStreetBets (“WSB” for short). Analyzing the causal interaction in social media helps people gain a more comprehensive and profound understanding of this online Wall Street movement. We use the WSB data set to construct causal networks and demonstrate the evolution of causality between GameStop stock price and WSB Redditors sentiment. We further analyzed the causality between GameStop stock price, WSB, and cryptocurrency. The discovery convinced us that Redditor in WSB did dominate and promote this movement and extended the battle to cryptocurrency market.