CoStar Hit With Class-Action Suit Claiming It's A Monopoly That 'Destroyed Competition'

Why It Matters

If the suit succeeds, CoStar could be forced to unwind exclusive contracts and lower fees, reshaping pricing and data‑ownership norms across the CRE industry.

Key Takeaways

• CoStar controls roughly 80% of online CRE listings market
• Grand & Co. alleges Sherman Act violations and price‑fixing
• CoStar requires $300‑$1,000 monthly subscriptions for all brokers
• Crexi also sues CoStar, intensifying antitrust pressure

Pulse Analysis

The commercial‑real‑estate sector has become increasingly digital, and CoStar Group has emerged as the de‑facto gatekeeper, aggregating listings on LoopNet and other platforms. Its near‑monopoly—estimated at 80% of internet‑based CRE listings—has drawn scrutiny from regulators who worry that such concentration can inflate subscription costs and limit data portability for brokers. By bundling services and demanding blanket subscriptions, CoStar has set a high barrier to entry, discouraging smaller platforms from gaining traction.

Grand & Co.'s class‑action filing intensifies the legal battle, accusing CoStar of Sherman Act violations, exclusive contracts with industry giants CBRE, JLL, and Cushman & Wakefield, and coercive pricing that forces brokers into costly, all‑inclusive plans. The complaint also highlights CoStar's historical tactics, including past lawsuits against rivals and the 2011 LoopNet acquisition for $860 million, which cemented its dominance. While CoStar points to Crexi as evidence of competition, Crexi's parallel antitrust suit underscores a broader industry pushback against perceived data‑ownership monopolies.

The outcome of these lawsuits could reverberate throughout the CRE market. A ruling that curtails CoStar's exclusive agreements or mandates more open data standards would likely lower subscription fees and spur innovation among emerging platforms. Conversely, a dismissal could reinforce CoStar's market power, prompting further consolidation. Stakeholders—from large brokerages to independent agents—should monitor the case closely, as it may set precedent for how digital marketplaces are regulated in the real‑estate sector.