Cumulus Media Inc. Class A Common Stock. Replay the stock market charts of CMLS day by day back to 2003. Open long and short positions without spending any money. Cumulus Media Inc. owns and operates radio stations in the United States. The company operates in two segments, Radio Station Group and Westwood One. It sells commercial advertising time to local, regional, and national advertisers; and network advertising. The company offers content through approximately 445 owned-and-operated stations in 90 United States media markets; and approximately 8,200 broadcast radio affiliates and various digital channels. As of December 31, 2016, it operated five radio stations under local marketing agreements. Cumulus Media Inc. was founded in 1997 and is based in Atlanta, Georgia.