The U.S. Supreme Court has declined to hear an appeal from Real Estate Exchange Inc. (REX), a now-defunct real estate brokerage that accused Zillow and the National Association of Realtors (NAR) of violating antitrust laws in the online home listings market. The decision leaves in place a lower court ruling that sided with Zillow and NAR, effectively ending a case that questioned competition standards in the digital real estate sector.
Case background and claims
Filed in 2021, REX’s lawsuit targeted NAR’s “no-commingling” rule — a policy that allowed Zillow and other NAR-affiliated platforms to display listings from multiple listing services (MLS) separately from non-member properties. REX argued that this practice restricted consumer access and unfairly disadvantaged independent brokers by making their listings harder to find.
The company also accused Zillow of misleading homebuyers by redesigning its website to prioritize NAR-affiliated listings over those from competitors. REX claimed that Zillow’s compliance with the rule amounted to a conspiracy that suppressed competition in violation of federal antitrust law.
Court rulings and legal reasoning
A federal judge dismissed REX’s antitrust claims before trial, and in March 2025, the Ninth U.S. Circuit Court of Appeals upheld that decision. The appellate court found that Zillow’s adherence to NAR’s rule did not constitute an illegal conspiracy, emphasizing that the policy was optional and later rescinded.
REX took the case to the Supreme Court, warning that the appellate decision could create a loophole allowing trade associations to implement “optional” rules with anticompetitive effects. The justices declined to take up the appeal, effectively confirming the lower courts’ rulings.
REX’s separate consumer deception claim proceeded to trial in 2023, where a jury ruled in Zillow’s favor.
Responses from involved parties
Zillow welcomed the Supreme Court’s decision, calling it “a reaffirmation of our commitment to transparency, innovation, and putting consumers first.” The National Association of Realtors similarly praised the outcome, noting that its policy had been voluntary and did not violate antitrust principles.
A spokesperson for REX did not comment on the court’s decision. The company, which ceased operations in 2023 amid mounting legal and financial challenges, had positioned itself as a disruptor to traditional real estate models.
Broader implications
The ruling represents a significant victory for Zillow and NAR, reinforcing the legal boundaries of collaboration between real estate platforms and trade associations. It also underscores the difficulty smaller, tech-driven brokerages face when challenging established industry frameworks.
For the broader housing market, the decision highlights ongoing questions about visibility, access, and competition in online real estate listings — an arena increasingly shaped by a few dominant platforms.
Source: Reuters
