Home Business Exclusive: Online mattress retailer Casper to hire IPO underwriters – sources Business Exclusive: Online mattress retailer Casper to hire IPO underwriters – sources By Genpie - March 27, 2019 144 0 Facebook Twitter Google+ Pinterest WhatsApp Casper Sleep Inc, the U.S. online mattress retailer whose investors include actor Leonardo DiCaprio and rapper 50 Cent, is seeking to hire underwriters for an initial public offering (IPO), according to people familiar with the matter.