The events giving rise to the suit took place during a short period of market volatility caused by aggressive trading in a handful of securities.1 Purchases of the relevant securities grew rapidly during the week before January 27, 2021, due to their surging popularity among retail investors in the online community.

1 The relevant securities, referred to colloquially as “meme stocks” due to their popularity in online discussion forums, include GameStop (“GME”), AMC Entertainment (“AMC”), Bed Bath & Beyond (“BBBY”), BlackBerry (“BB”), Express (“EXPR”), Koss (“KOSS”), Nokia (“NOK”), Tootsie Roll Industries (“TR”), and Trivago NV (“TRVG”).

4 The Amended Complaint defines the “No-Fee Brokerage Trading App [m]arket” as the downstream or consumer-facing relevant product market consist[ing] of zero account-minimum, no-fee brokerages that 1) offer a user-friendly mobile app to Retail Investors to place orders to buy and sell stocks, exchange-traded funds (ETFs), and other securities or investments strategies such as trading on margin or using options strategies, and 2) receive payment for order flow from market makers instead of fees from Retail Investors[.]

The instant appeal concerns only one of those four tranches—the “Antitrust Tranche.” On July 27, 2021, Plaintiffs in the Antitrust Tranche filed the original Consolidated Class Action Complaint, asserting conspiracy claims against multiple brokers, including Robinhood, and one market maker, Citadel.

9 The Amended Complaint also describes tense communications between representatives of Citadel and Robinhood in the days leading up to and following the trading restrictions, which Plaintiffs allege are indicative of an agreement between Defendants to prohibit purchases of the relevant securities.