Levi's are proving an enduring wardrobe investment for the descendants of the inventor of blue jeans.

The Haas family, which traces its lineage to company founder Levi Strauss, owns almost 59 percent of the San Francisco-based apparel maker that filed for an initial public offering on Wednesday. The firm is said to be valued at $5 billion, according to CNBC, giving the family a combined net worth of at least $2.5 billion.

Bavarian-born Strauss emigrated to New York in 1848 and was soon lured to San Francisco by the California Gold Rush. Failing to find much gold, he started a West Coast branch of his brothers' wholesale dry goods business and called it Levi Strauss & Co. One day he received a letter from a customer, a Nevada tailor named Jacob Davis, who'd started designing pants with rivets to make them last longer. He needed a business partner and Strauss was eager to collaborate.