Punk rock in the United States underwent a resurgence in the early to mid-1990s. Punk rock at that time was not commercially viable, and no major record label signed a punk rock band until Green Day's breakthrough in 1994. Both these factors contributed to the emergence of a number of independent record labels, often run by people in bands in order to release their own music and that of their friends. The independent labels Lookout! Records, Fat Wreck Chords and Epitaph Records achieved commercial success.