Rental screening startup 100 today announced that it has acquired Cobblestone Labs Inc., a fraud detection and income verification platform built by former engineers from corporate card company Ramp Business Corp., in a deal that folds an artificial intelligence-native underwriting engine into 100’s rental screening platform.

Terms of the acquisition were not disclosed. As part of the deal, Cobblestone co-founders Jason Scharff and Jack Mastrangelo will join 100 as strategic advisers.

Founded in 2023 and based in New York, Cobblestone offers software that helps institutional landlords reduce delinquency and catch fraud during the leasing process. The platform combines application data with an income verification and fraud detection system aimed at identity fraud, income fraud and synthetic identities across residential real estate.

Its founding team met at Ramp before turning to property technology. Cobblestone went through Y Combinator’s Winter 2023 batch and counts the accelerator among its backers.

For 100, the acquisition adds an underwriting engine its founders said was modeled on the kind of financial systems Cobblestone’s team built in fintech. The combined platform pairs that engine with what 100 describes as an architecture that draws on multiple data sources, multiple large language models cross-checking one another and human review.

The deal comes as rental fraud climbs across the apartment rental market. The U.S. Federal Bureau of Investigation tracked $275 million in real estate fraud losses in 2025 and generative AI has made it cheaper to produce convincing fake personas and forged documents at scale. A National Multifamily Housing Council survey found 93% of members experienced fraud last year and more than 70% did not catch it until after a tenant had moved in. Consulting firm Deloitte Touche Tohmatsu Ltd. projects AI-driven fraud losses will reach $40 billion by 2027.

“Cobblestone was built from our experience as early engineers at Ramp, where we helped build some of the most advanced financial underwriting systems in the market and realized the real estate industry deserved the same,” Scharff said.

Alongside the acquisition, 100 said it had been named a preferred partner by several operators on the NMHC Top 50 list, including Asset Living, Knightvest Residential and RAM Partners. The designation signals that some of the industry’s largest operators are standing up the platform to speed application processing and reduce bad debt. The company said customers report a 67% increase in application velocity and a 35% drop in delinquency.

100, formally Hi Cavalry Inc., was founded in 2023 and raised $5.2 million in pre-seed funding in October 2024 in what was described as the largest ever proptech pre-seed round at the time. The company says it has sustained month-over-month revenue growth above 25%.

Image: Cobblestone