The global security services industry was worth 128 billion U.S. dollars in 2018. The largest share of this market was held by Europe at 28.1 percent, followed by Asia - excluding Japan - and then North America. The revenue of the security services industry generated 35 billion U.S. dollars in the United States in 2018. In 2017, around 810,000 security guards were employed by the industry in the United States.
The three largest companies in the U.S. outsourced security services market are G4S, Securitas and Allied Universal Security Services, with a combined revenue of 12.6 billion U.S. dollars reported in 2017. This was almost half of the 25.5 billion U.S. dollars revenue reported in the U.S. outsourced security services market for that year. Of the fastest-growing companies, the largest company was Allied Universal Security Services, who reported 5.5 billion in revenue in 2017. The Pennsylvania-based company specializes in facility services, which include security systems, janitorial services, and staffing.