Indigo Partners is a private equity firm based in the United States, specializing in the airline and travel industries. Founded in 2003 by Bill Franke, the firm focuses on investing in low-cost carriers and has a reputation for enhancing operational efficiency and profitability in its portfolio companies. The firm has made significant investments in several airlines, including Wizz Air, Spirit Airlines, and Frontier Airlines. Indigo Partners aims to create value through strategic management and operational improvements, helping these airlines expand their market presence and improve customer service while maintaining low fares.