Magnite has alleged Google’s practices locked publishers into its systems and steered business to its own exchange, harming rivals and stifling innovation.

The Google brand logo (logo, symbol, emblem) can be seen at the company's stand at the IAA Mobility (International Motor Show) in a hall at Messe München (Bavaria, Germany) on September 12, 2025. (Photo by Matthias Balk/picture alliance via Getty Images)

Prabhjote Gill·Stocktwits

Updated Sep 16, 2025 | 9:27 AM GMT-04

Share this article

Magnite (MGNI) announced on Tuesday that it has filed a lawsuit against Alphabet’s (GOOG/GOOGL) Google in the U.S. District Court for the Eastern District of Virginia, seeking damages tied to antitrust violations.

Magnite’ stock rose more than 1% in pre-market trade on Tuesday. On Stocktwits, retail sentiment around the stock remained in ‘neutral’ territory over the past day. Meanwhile, Alphabet’s stock edged 0.46% higher but retail sentiment continued to trend in ‘bearish’ territory even as chatter rose to ‘high’ from ‘normal’ levels.

One of the largest independent sell-side advertising platforms alleges that Google’s practices locked publishers into its systems and steered business to its own exchange, harming rivals and stifling innovation. “Google did not earn its privileged position in the ad tech ecosystem through innovation or competition on the merits. Instead, it first bought its way to dominance,” the lawsuit said. The move follows an April 2025 federal ruling that found Google “willfully engaged in a series of anticompetitive acts” to maintain monopoly power in ad exchange and ad server markets.

Magnite CEO Michael Barrett said the company was built to help publishers improve ad revenue through technology and transparency, but argued that Google’s self-preferencing practices made that mission harder to achieve. He added that Magnite hopes the legal action will help restore competition and innovation across the digital ad ecosystem.

Magnite had previously signaled potential action. On its second-quarter (Q2) earnings call, Barrett told investors the company was “looking at” litigation and saw “a lot of merit there.”

The lawsuit follows similar actions by publishers and rivals. Gannett filed a complaint in 2023, and in August, supply-side platform OpenX sued Google in federal court, accusing it of abusing its dominance through a decade-long pattern of self-preferencing.

Subscribe to The Litepaper

All Newsletters

Get the daily crypto email you’ll actually love to read. It's value-packed, data-driven, and seasoned with wit.

For updates and corrections, email newsroom[at]stocktwits[dot]com.

Read about our editorial guidelines and ethics policy