Core Viewpoint - A U.S. federal judge has permitted the inclusion of new evidence in a class-action lawsuit against the Solana-based memecoin platform Pump.fun, following the emergence of nearly 5,000 internal chat messages that may reveal insider trading and transaction manipulation [1][6]. Group 1: Legal Proceedings - Judge Colleen McMahon of the U.S. District Court for the Southern District of New York has allowed plaintiffs to amend and refile their complaint against Pump.fun, Jito Labs, the Solana Foundation, and related executives [2]. - The lawsuit, initiated by Diego Aguilar, Kendall Carnahan, and lead plaintiff Michael Okafor, represents investors who purchased tokens on Pump.fun between March 1, 2024, and July 23, 2025, and subsequently incurred losses [4]. - Plaintiffs are required to file their second amended complaint by December 19, 2025, with motions to dismiss due by January 23, 2026 [7]. Group 2: Allegations and Practices - The case centers on allegations of maximal extractable value (MEV), a practice that allows validators or traders to profit by reordering transactions within a blockchain block [3]. - Plaintiffs claim that the defendants operated a "Pump Enterprise" that provided insiders with priority access to newly launched tokens while misleading the public about the fairness of these launches [4]. - It is alleged that Solana Labs' validator infrastructure enabled transaction ordering control, and tools from Jito Labs allowed certain participants to pay for priority execution [5]. Group 3: Financial Impact - The lawsuit builds on previous litigation that accused Pump.fun of generating over $722 million in revenue while causing retail traders losses estimated between $4 billion and $5.5 billion [8]. - Insiders reportedly bought tokens at low prices before public trading, leading to rapid price increases and leaving retail buyers to absorb losses once insiders exited [6].