But Zillow insists that Zillow Preview is “not at all the same” as MRED’s alleged scheme. In a statement to Ars, Zillow defended its pre-market listing product as “available for any buyer to see and aligned with our transparency standards.”

“Private listings networks are just that—private, and only available to buyers working with a specific brokerage or agent,” Zillow said. “The goal of Preview is to help sell the house. The goal of PLNs is to hide the house to force more buyers into working with your brokerage.”

Home buyers in the US have in the past few years faced hardships, including “persistently high mortgage rates and home prices,” since the housing inventory has never returned to pre-pandemic levels, a 2026 Experian forecast said. While inventory is expected to modestly increase this year, Zillow’s legal fight suggests some brokerages may be motivated to increasingly hide new listings to increase profits.

Zillow worries that the MRED/Compass plan will inevitably block platforms that are promoting more transparency from competing with powerful private listings network providers. That will disadvantage both buyers and sellers in major markets like Chicago, Zillow alleged.

“Defendants’ conspiracy harms home buyers and sellers by incentivizing brokerages to withhold listings from the market only until the listing fails to sell privately, thus erecting barriers to information, exacerbating the accessibility and affordability crisis, and reducing the pool of buyers and listings that makes the real estate market efficient and competitive,” Zillow alleged.

In its complaint, Zillow said that MRED and Compass “control over 99 percent of the market for Chicagoland real estate listing platforms.” Allegedly, they’ve worked “in lockstep” and “in secret” to “leverage MRED’s monopoly power and control over Chicagoland listing feeds to force competitors like Zillow to display unwanted private listings, abandon pro-consumer listings policies, and block nascent competing offerings that preference access over exclusivity.

“MRED and Compass have colluded to turn back the clock on consumer transparency at the exact moment American families can least afford it, cutting off competition, hiding homes and engineering a market that extracts more from buyers and sellers so Compass can pocket more on every deal,” Zillow told Ars.