Aeropostale, the clothing chain for teens, is offering the biggest sales discount in America for private-equity firms seeking a deal at the mall. After the chain reported its smallest annual profit in at least a decade and forecast a first-quarter loss, its stock slumped last week by the most in two months.

That left the firm valued at 0.46 times its revenue in the last year, the cheapest among similar-sized US specialty-apparel retailers, according to recent data.