Compass, which has been heavily pushing its private exclusive listings and its three-phased marketing plan, took issue with the policy and filed an antitrust lawsuit against Zillow in late June.
On Friday, Compass filed a supplemental brief ahead of the hearing, as required by the court. Compass opened the brief by claiming that a statement made by Zillow in mid-October “confirms” that the company has “successfully quashed competition.”
On Oct. 13, 2025, Zillow published a post on its investor website noting that since Zillow began notifying agents of non-compliant listings over the summer, roughly 90% of agents who receive a notice only receive one. According to Zillow, this means that the initial notices have resulted “in most agents making sure their next listing was available widely and aligned with the Zillow standards.”
“Only about 10.5% of agents who received notices get two — meaning almost 9 in 10 agents who receive a notice from Zillow are first‑timers who do not continue to only selectively market their listings through private listing networks,” the post states.
According to Zillow this shows that the majority of agents want to keep their clients’ listing broadly visible. However, Compass claims that this shows Zillow used “its immense power to block approximately 90% of the agents from publicly marketing properties off Zillow’s website—something agents across the country were previously doing at their clients’ express request and instruction.”
Zillow stopped competition, says Compass
According to Compass, this shows that Zillow is “so powerful that by sending just an email threatening to punish agents for marketing off Zillow’s website, Zillow stopped competition in the online home search market and destroyed a significant challenge to its monopoly through intimidation and punishment instead of competing fairly for the home seller listings that fuel its website.”
The plaintiff states that this is evidence of Zillow using its alleged monopoly power to intimidate agents and deprive sellers of options. Compass also argues that instead of competing to gain a home seller’s listing by offering “differentiated home marketing products,” Zillow is using its size and power to force agents and home sellers to put their listing on its site.
“Zillow is controlling the entire real estate industry. Zillow is not just dictating how home sellers market on Zillow but is dictating how home sellers market properties outside of Zillow and forcing home sellers to provide listings to the Multiple Listing Services,” the filing states.
The filing goes on to claim that in order to preserve its alleged monopoly, Zillow has colluded with other industry players including Redfin and the MLSs, none of which are named as defendants. Through discovery, Compass claims that in a phone call between Zillow’s CEO and Redfin’s CEO, the two firms “agreed to implement versions of the Zillow Ban within two business days of each other.”
Finally, Compass also claims that the policy harms transparency and as such harms consumers because instead of allowing the public marketing of properties as they are being prepared for the market, it hides these properties from the public.
Zillow has until Nov. 12, to respond to Compass’s supplemental brief, ahead of the preliminary injunction hearing which is slated to begin on Nov. 18, 2025.
While Compass will not be gaining access to draft copies of Redfin CEO Glenn Kelman’s blog post announcing his firm’s listing standards policy, Judge Jeanette Vargas, who is overseeing the lawsuit, is allowing Compass to call on a Compass agent as a witness, a move that was earlier disputed by Zillow.
Zillow did not immediately respond to HousingWire’s request for comment on Compass’s latest allegations.
