The net worths of Forever 21 cofounders Jin Sook and Do Won Chang have plunged alongside the store’s sales. Its founders lost their billionaire status in July according to Forbes, and the retailer filed for bankruptcy on September 29.

At the company’s peak in 2015, Jin Sook and Do Won Chang had a combined net worth of $5.9 billion, according to Forbes. Their combined fortune has fallen to $1.6 billion – or $800 million each – as the fast fashion chain enters bankruptcy proceedings. Forever 21 will close 350 stores ac cross the globe, but will continue to operate in select locations and online.

“We are confident this is the right path for the long-term health of our business,” Forever21 said in a letter to customers published on its website. “Once we complete a reorganization, Forever 21 will be a stronger, more viable company that is better positioned to prosper for years to come.”

The married couple founded Forever 21 in Los Angeles in 1984 after emigrating from South Korea three years prior. Their first location, originally called Fashion 21, was 900 square feet and stocked merchandise the Changs purchased at wholesale close-out sales, according to Forbes.

Read more: We shopped at Forever 21 and H&M and saw firsthand why one store is clearly outperforming the other

In June, Business Insider's Bethany Biron visited a Forever 21 store and its fast-fashion rival H&M in New York's Westfield World Trade Center mall and found that H&M's well-lit and organized store drew more shoppers than Forever 21's sparsely stocked subterranean location.

Forever 21 is privately held and does not release its sales numbers, but the fast-fashion giant has recently closed stores in major markets, including London and China, Business Insider previously reported. Forever 21 stores in the US have also begun to shrink in the US, Forbes reported, as several two-story mall locations gave their second floor to other stores, including Dave & Buster's and Ulta Beauty.