Judge Denies Zillow Motion in Compass/MRED 'Collusion' Lawsuit

The legal landscape in the United States is never anything less than enthusiastically active, and Zillow is currently at the centre of an existential argument in American real estate, around who controls listings, where and when they should appear, and whether private listing networks are the next major shift in discovery.

In a potentially paradigm-shifting set of lawsuits, Compass previously filed an antitrust action against Zillow, alleging it used its monopoly power to enforce unethical rules on how consumers access real estate listings nationwide, before withdrawing the lawsuit after Zillow amended its controversial listings ban. Watch Online Marketplaces' podcast with Compass here.

And in May of this year, Zillow filed a lawsuit against the MLS operator Midwest Real Estate Data (MRED) for anticompetitive behaviours, alleging collusion between Compass and MRED to switch off Zillow's access to listings.

Also in May 2026, Zillow filed an injunction allowing it to retain access to Chicagoland listings during legal proceedings, after MRED threatened to cut off Zillow's feed in response to its controversial Listings Access Standards policy enacted in April 2025, which threatened to ban listings that were shared via private listings networks without being uploaded to the requisite MLS's, thereby keeping Zillow's platform fully up to date.

But this week, a judge wrote that a Zillow motion "makes no sense" after ruling in favour of MRED.

Judge John Tharp said Zillow's motion for the court to label MRED's decision to revoke access to its listing feed as anticompetitive did not hold water, writing that Zillow's argument that publishing 'stale' inventory that has already been listed and potentially sold via a private listings network was lacking:

"Without a comprehensive inventory of listings, including those on private listing networks—Zillow contends—it will be unable to compete effectively because listings that have previously been marketed on a PLN are stale and of less interest to buyers. That makes no sense."

The judge denied Zillow's motion for an injunction, cancelling a restraining order over its listing feed in Chicago. In other words, MRED now has the legal right to switch off Zillow's listing feed for the region while the case goes to arbitration.

The long and short of the state of the lawsuit as things stand is that an MLS has autonomy in siding with a portal or a brokerage. It's a major blow for Zillow, and a major win for brokerages with private listing networks.

According to Judge Tharp's summary of the lawsuit to date, MRED was keen for members to notify it if Zillow approached them with requests to access listing feeds independently of the MLS, while Compass terminated several existing direct-feed arrangements with Zillow in Chicagoland, and then nationwide; with both parties then entering negotiations to launch a nationwide MLS that would grant it the power to switch off Zillow's access to listings in several other territories.

Following the announcement of MRED’s national expansion, Compass agents outside Chicagoland began entering listings into MRED, while Zillow began suppressing listings in those territories under the terms of its updated listings access standards ('Zillow ban'). In retaliation, MRED suspended Zillow's access to its listings feeds. Zillow counterattacked in court, alleging violations of the Sherman Act and an unlawful alliance between MRED and Compass.

Selected quotes from September's 54-page court order include:

The evidence does not sufficiently distinguish that...MRED and Compass independently pursued aligned interests. The record shows extensive communications, opportunities to coordinate, overlapping opposition to Zillow’s Standards, and actions that reduced Zillow’s access to listing data. 

[Even though] those communications are consistent with Zillow’s theory [that MRED and Compass colluded], they are also compatible with Compass independently acting to preserve its preferred marketing strategy and MRED’s independent interest in enforcing its rules and pursuing the interests of its members. Zillow has not, therefore, identified evidence that “tends to exclude” the possibility of independent action.

Zillow has not made the required strong showing that MRED and Compass agreed to cut off Zillow’s access to residential real estate listings. Its direct evidence does not establish that agreement, and its circumstantial evidence does not sufficiently distinguish the inference of agreement from the competing inference of independent conduct. Zillow therefore has not made the required showing of an agreement [that contravenes the Sherman Act].

That conclusion is sufficient to defeat Zillow’s claim at the preliminary injunction stage.

[Meanwhile] Zillow argues that the alleged agreement is a horizontal group boycott and therefore constitutes a per se unreasonable restraint of trade. The Court disagrees.

The Supreme Court has long treated certain group boycotts as unlawful per se. “The common attribute of per se illegal boycott is a concerted attempt by a group of competitors at one level to protect themselves from competition from non-group members who seek to compete at that level."

Zillow asserts that “Compass, MRED and Zillow are horizontal competitors in the Listing Creation and Distribution market.”

That relationship is not self-evident, nor is Zillow’s proposed market one that courts have acknowledged or recognized. MRED does not create listings; it operates an MLS that collects and distributes listing information among its members—including both Zillow and Compass. Compass is a brokerage whose agents market and sell real estate—that is, it creates listings. Zillow operates a platform that neither creates nor distributes listings but rather receives and displays them.

Second, Zillow has not demonstrated that “the boycott is designed to protect the boycotters from competition with the target.” In other words, the anticompetitive character of the conduct alleged is not sufficiently obvious to justify condemnation without further analysis.

Here, the alleged anticompetitive conduct—cutting off Zillow’s access to residential real estate listing feeds—is not itself price fixing, market allocation, bid rigging, or other restraint whose anticompetitive character courts have long treated as self-evident.

The record presents plausible explanations for the conduct other than an effort by MRED and Compass to protect themselves from competition with Zillow. MRED contends that its actions reflect enforcement of rules governing the distribution and use of listing data, while Compass contends that its conduct reflected its own listing and marketing strategy.

The existence of these plausible alternative explanations is relevant because it prevents the Court, on the present record, from characterizing the alleged agreement as a “naked restraint of trade with no purpose except stifling of competition.”

Accordingly, Zillow has not made the strong showing necessary to establish a per se unlawful group boycott.

The Court therefore concludes that Zillow has not made a strong showing that its proposed market for Residential Real Estate Listing Creation and Distribution corresponds to the commercial realities of the industry or encompasses services that are reasonably interchangeable. Zillow has not sufficiently defined a relevant market, but even if it had, it would also be required to show that MRED and Compass possess sufficient market power for the challenged restraint to produce substantial anticompetitive effects.

Zillow has also failed to make the required showing that the alleged restraint has caused a substantial anticompetitive effect in that market. The record also identifies plausible procompetitive effects from the challenged conduct. MRED’s national expansion could permit it to compete with other MLSs for members and listings, potentially increasing the choices available to brokers, agents, and sellers.

The proof of the pudding, moreover, is in the eating. Despite the ongoing dispute, Zillow has never enforced its Standard in Chicagoland, and has presented no evidence of any “downward spiral” in Zillow’s business.

Regarding the decision, MRED said:

The court’s preliminary injunction ruling in favor of MRED marks an important victory not only for MRED, but also for MLSs, brokers and the cooperative marketplace nationwide.

A Zillow statement said:

Today’s ruling is a step back for Chicago home buyers and sellers, at least temporarily. Buyers, sellers and their agents depend on a fair, transparent housing market to find their dream home and sell for the best price. MRED and Compass are jeopardizing that to line their own pockets.

Compass said:

Any effort to punish consumers for exercising that choice is anti‑competitive and harmful to consumers. Real estate professionals have a fiduciary duty to serve their clients; Zillow does not.