According to the traders, Robinhood and Citadel had developed an important and lucrative relationship. The relationship was crucial to their respective businesses. They implemented the scheme to protect each other: Defendants allegedly conspired to prohibit Retail Investors from purchasing the Relevant Securities to save Citadel from hemorrhaging losses due to its accumulation of large short positions, and to save Robinhood's business model, which depends predominantly on the lucrative order flow payments that Robinhood receives from Citadel. The plaintiffs claim that Robinhood and Citadel were in a collusive agreement which prevented the market from operating in a competitive manner as it would have absent the restraint. As such, Defendants' agreement introduced price artificiality by preventing the trading price from reflecting the supply and demand conditions that would have otherwise prevailed in a competitive market.