Elaborating on her proposal to break up the biggest tech companies, Democratic presidential hopeful Elizabeth Warren said Apple (AAPL) needed to be split up, as well.

Last week, Warren had said that companies like Facebook (FB) , Amazon (AMZN) and Alphabet (GOOGL) had become too dominant and that breaking them up would spur competition and force the companies to be more responsive to users. In particular, Warren said that companies should not be able to both own major platforms and sell their own goods and/or services on them.

In an interview with the Verge over the weekend, Warren indicated that she would include Apple among the tech companies that needed breaking up.

"Apple, you've got to break it apart from their App Store," Warren said. "It's got to be one or the other. Either they run the platform or they play in the store. They don't get to do both at the same time."

Warren noted that both running a platform and selling on it gives companies two big advantages.

"One, you've sucked up information about every buyer and every seller before you've made a decision about what you're going to to sell," Warren said. "And second, you have the capacity - because you run the platform - to prefer your product over anyone else's product. It gives an enormous comparative advantage to the platform."

Michael Pachter of Wedbush Securities pointed out, however, that any action to break up a company on these grounds would have to prove that it held monopoly power. Pachter noted that the App Store works only on Apple devices, so it's not "even remotely arguable as a monopoly."  

"Under current law, there is zero chance the law could be changed to trigger a break up of Apple or any other tech company," Pachter wrote in an email. "They simply don't have monopolies under current law. They could be broken up if the law changes, but Congress can't agree on something like this."

Daniel Ives, Pachter's colleague at Wedbush, noted, though, that there are investor concerns about Apple, given a pending Supreme Court antitrust case involving the App Store, and Netflix's recent decision to leave the App Store to avoid paying a fee to Apple. 

"These Warren comments fan the flames of these worries for tech investors on the Apple story," Ives said in an email.

Apple shares rose 3.5% to $178.90 on Monday following an upgrade from Bank of America Merrill Lynch.

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