A Texas federal judge has ruled that American Airlines violated federal law by allocating employees' retirement plans to investment companies focused on environmental, social, and governance (ESG) products. This decision is seen as a victory for critics of ESG investing, emphasizing that pension funds should prioritize financial returns over social and environmental considerations. The ruling could expose nearly every pension plan in the U.S. to potential fiduciary mismanagement lawsuits, particularly targeting what the judge described as 'cartel-like' practices among 401(k) investment managers. The case specifically addressed American Airlines' fiduciary duty of loyalty in its dealings with BlackRock's ESG funds, raising questions about the legality of ESG-focused investment strategies in retirement accounts.