The ruling may expose Apple to payments of hundreds of millions in dollars in damages, CNBC reported. Based on its own interpretation of the legal precedent, Apple argues that consumers can only sue the developers due to their role setting prices.
With Monday's ruling, it will kick the case back to a lower court, where iPhone owners and Apple will continue what is likely to be a lengthy legal battle.
Apple has argued that they are not a monopoly as consumers could always purchase apps from other app stores by buying another device, a somewhat ridiculous position. During oral arguments past year, conservative Justice Samuel Alito questioned if the precedent that Apple cited now "stands up" in the digital ecosystem.More news: Ireland Bans US Hate Pastor, First Ban Under 1999 Act
Shares hovered around $187 a share, down 5%, in mid-morning trading.
Tom's Hardware has reached out to Apple for comment, but did not receive an immediate response. This commission structure results in higher prices for consumers, the plaintiffs argued.
"If accepted, Apple's theory would provide a roadmap for monopolistic retailers to structure transactions with manufacturers or suppliers so as to evade antitrust claims by consumers and thereby thwart effective antitrust enforcement".More news: Emery: We want to play with Mkhitaryan in Baku
The opinion, authored by Justice Brett Kavanaugh, declined to take a specific stance regarding Apple's business practices.
This story will be updated if or when Apple responds.
Apple said that it was an agent for app developers and that it neither owned nor sold the apps itself. Apple said the consumers were indirect purchasers, at best, because any overcharge would be passed on to them by developers.More news: 'Shorty' Florenzi scoffs at Juventus star Ronaldo: He reckons he's entitled
If a new report is anything to go by, Apple is getting ready to abandon a series of older iPhones with the release of iOS 13 the next September. If an app is overpriced, the fault lies with developers and not Apple, the iPhone maker claimed. They were supported by 30 state attorneys general, including from Texas, California and NY. "But if Apple does lose, one possible outcome is that Apple might be forced to allow consumers to install apps from outside the App Store".