Amazon can steer market-wide prices without ever colluding—exposing a gap in antitrust law that the FTC is now fighting to close.

Companies are increasingly using pricing algorithms and other AI systems to develop and improve their ability to promptly respond to market conditions, innovate product offerings, and set prices.

Concerns and challenges raised in the past few years by lawmakers, enforcers, and private plaintiffs about algorithmic pricing, particularly where algorithms are based on pooled competitor data, began ...