OS Group Wants to Build the Infrastructure Layer for Resale Inventory Sourcing

Quick Facts

OS Group projects $50 million in revenue by end of 2025, up from $1 million in 2020
The U.S. secondhand apparel market is expected to reach $78.8 billion by 2030, growing at 5x the rate of the broader clothing market
OS Group has onboarded 200 live shopping sellers and sources footwear from 800-plus suppliers across 30 to 40 countries

The resale economy is maturing fast, and the infrastructure holding it together is still being built. A growing network of independent sellers is doing millions of dollars in business on platforms like TikTok Shop, Whatnot, and StockX. But sourcing inventory for those sellers has remained fragmented, relationship-driven, and often risky.

OS Group, a business-to-business company founded in 2019 by 24-year-old Oscar Rachmansky, is trying to fix that. The company scaled from $1 million in revenue in 2020 to a projected $50 million by the end of 2025. Rachmansky describes the model as focusing on what he calls the new wholesale economy.

The company operates similarly to wholesale marketplace Faire, but for independent resellers. Sellers sign up and browse centralized inventory sources to stock their virtual shelves. OS Group brokers bulk buyouts from other resellers and boutiques sitting on excess stock. Its footwear supply comes from more than 800 sellers across 30 to 40 countries, managed by a team that has grown from one person to 25 employees.

A Platform Play

OS Group recently launched a formal B2B platform giving qualified buyers access to sneakers and streetwear inventory available for immediate wholesale purchase and fulfillment. “Modern retail increasingly depends on inventory that exists outside traditional wholesale channels,” Rachmansky said. “Our goal is to build the infrastructure layer that connects fragmented supply with professional B2C demand.”

The company is also expanding into live shopping. It has onboarded roughly 200 sellers to a specialized platform that manages sourcing and sales for live channels including Whatnot, TikTok Shop, and eBay Live. “We’ve been slowly building momentum on the live shopping front since the beginning of the year,” Rachmansky said. “We just see a ton of opportunity on that front.”

The timing is deliberate. Total merchandise value on Whatnot more than doubled from $3 billion in 2024 to $8 billion in 2025. TikTok Shop grew U.S. sales 108% in 2025, reaching $15.82 billion and commanding 18.2% of total U.S. social commerce. One in eight live sellers on Whatnot works the platform full-time.

The Brand Relationship Problem

The sourcing side carries real risk. Nicole Buzo and Heather Green run Mama’s Sweet Repeats, a fashion and footwear shop on Whatnot. They confirmed that multiple brands supply them directly, but said those relationships are under NDA. The brands do not advertise this channel. Some deals require that product only be sold through live shopping platforms, not traditional retail.

“We get hundreds of emails daily with people offering to sell us inventory,” Buzo said. “I have to do in-depth research on each of our suppliers to make sure they’re legit, that they’re not being sued.”

Buzo said a centralized marketplace like OS Group’s platform would benefit sellers, but brands may resist the transparency. “A one-stop shop would be great, but a lot of brands wouldn’t be so fond of being on a master list,” she said. “The brands want everything to sell at full price.”

Market Context

The broader secondhand apparel market hit an estimated $257 billion globally in 2025, growing 13% year-over-year and representing roughly 10% of all global apparel spend, according to ThredUp’s 2026 Resale Report. The U.S. market grew 14% in 2024, its strongest rate since 2021, outpacing the broader retail clothing market by five times. Online resale grew 23% in the same period.

Gen Z and millennials are expected to drive more than 70% of resale market growth through 2030. About 80% of shoppers aged 18 to 24 actively buy secondhand apparel, with up to two out of five closet items sourced through resale platforms.

For resale operators, the core challenge is not demand. It is supply chain integrity at scale. OS Group is betting that professionalizing inventory access will determine which sellers survive the platform boom and which get buried in inbox spam from unverified suppliers.