Zillow-MRED Antitrust Battle Shifts From Courtroom to Private Arbitration

The high-stakes antitrust legal battle between Zillow and Midwest Real Estate Data (MRED) has officially shifted out of federal court and into private arbitration. U.S. District Judge John Tharp Jr. issued a ruling in Chicago on September 18, 2026, granting MRED's motion to compel arbitration, denying Zillow's preliminary injunction, and staying the entire federal lawsuit.

The dispute centers on the Chicagoland real estate market, where Zillow sued MRED and Compass International Holdings in May 2026. Zillow alleged that MRED and Compass colluded to hide listings and restrict Zillow's data feed access after Zillow implemented a policy refusing listings not available to the general public. Shortly after the lawsuit was filed, MRED cut Zillow's data feed access, though Zillow quickly secured a temporary restraining order to restore it.

Why did the federal judge move the case to arbitration?

Judge Tharp ruled that MRED was entitled to enforce a mandatory arbitration clause established in an agreement with MLS data feed provider MLS Grid, which specifically designates each MLS as a third-party beneficiary. Furthermore, the court determined that the claims against MRED and co-defendant Compass were too intertwined to separate.

As Judge Tharp noted in the ruling reported by HousingWire, MRED and Compass were alleged to be coconspirators, meaning all conduct by Compass would unquestionably be at issue in the arbitration against MRED.

“To say that the factual and legal issues underlying Zillow’s claims against Compass therefore substantially overlap with those that will be resolved in arbitration is an understatement,” Judge Tharp wrote. Legal experts like Brad Weber, a partner in Troutman Pepper Locke’s Antitrust Practice Group, explained to HousingWire that the judge used his discretion to stay the case to prevent rulings that might conflict with the private arbitration.

What does this mean for the public and future proceedings?

Because the dispute is heading to private arbitration, the proceedings will no longer take place in an open federal court. Brad Weber noted that arbitrations are generally private, meaning there will be no public filings or easily readable orders detailing the finer points of the case.

This aspect drew sharp criticism from Zillow. A Zillow spokesperson stated in reports by Real Estate News and Claims Journal that “MRED wants to move this case behind closed doors, away from the public scrutiny that anticompetitive conduct deserves.” Zillow called the outcome a step back for Chicago home buyers and sellers.

Conversely, Compass hailed the outcome. In a statement reported by Claims Journal, Compass asserted that “this decision affirms that choice belongs to the homeowner, and any effort to punish consumers for exercising that choice is anti‑competitive and harmful to consumers.”

What happens next for the litigants?

With the federal court case stayed, the claims against MRED will proceed through private arbitration. Harrison McAvoy, a partner at Mandelbaum Barrett PC, told HousingWire that while the ruling is not a final verdict on the merits, the court's findings showed deep skepticism regarding Zillow's showing of an alleged conspiracy between Compass and MRED. Litigants now face a choice between pushing through full arbitration or attempting to negotiate a settlement, which Brad Weber noted is a common path in antitrust disputes.