An e-commerce site involved in the sneaker resell market has raised $6 million thanks in part to rap legend Marshall Mathers. Stock market startup StockX aims at becoming the marketplace for sneakerheads. StockX claims sneaker resell is a $6 billion business.

The Detroit-based company confirmed on Wednesday that it closed on a round of funding that included investors such as Eminem, Wale and Mark Whalberg, Fortune reports. The funds raised will help expand StockX's line of watches and handbags, and also continue growing their sneaker business.

The venture aims to connect buyers to sellers through a live bidding market, the same way you would buy shares on a stock market. StockX then takes a percentage of the sales booked on their website. Launched about a year ago, it features Adidas, Jordan and Nike indexes that measure estimated U.S. resell sales over a 24 hour period.

Cleveland Cavaliers owner and Quicken Loans Chairman Dan Gilbert co-founded the venture along with its CEO Josh Luber. Luber said he came up with the idea for StockX because, "in the sneaker community and resell marketplace that's existed for as long as Air Jordan in 1985, there's never been a data-driven price guide."