Shenzhen has a close bond with Hong Kong, its next-door neighbor. Shenzhen supplies the majority of the poultry, eggs, fish, meat and dairy products to the Hong Kong market. It also supplies more than 1.1 billion cubic meters of drinking water consumed by Hong Kongers. The Daya Bay Nuclear Power Plant of Shenzhen provides electricity for Hong Kong. Hong Kong firms have always been the most important investors in Shenzhen and many Shenzhen firms have been listed on the Hong Kong stock exchange. With the view of a mega-metropolis formed by the two cities in the future, Shenzhen is considering this trend in its long-term plans.