thredUP is a fashion resale website for consumers to buy and sell secondhand clothing online. thredUP is part of a larger Collaborative Consumption movement, which encourages consumers to live in a more collective, sharing economy. ^{[undefined] [undefined]} Other U.S. companies in the recommerce industry ^{[undefined] [undefined]} with thredUP include Gazelle, uSell, Nextworth, and The RealReal. thredUP is advised by current Netflix CEO Reed Hastings and former eBay CEO, Brian Swette. Trinity Ventures, Redpoint Ventures and Highland Capital Partners have invested in the company.

In early 2009, James Reinhart, Chris Homer, and Oliver Lubin co-founded thredUP in Cambridge, Massachusetts, ^{[undefined] [undefined]} testing a stealth pilot for peer-to-peer online sharing of men’s dress shirts, ^[undefined] and in September 2009, they launched their first official product focused on swapping men’s and women’s clothes. ^[undefined] Due to underperformance in the men & women demographics, thredUP pivoted towards children’s clothing in April 2010. ^[undefined] This pivot resulted in greater growth, which attracted the attention of the venture capital community. ^[undefined]