Visa Inc. is the world's second-largest card payment organization after China UnionPay, according to the annual value of card payments transacted and the number of cards issued. As China UnionPay’s transactions are mainly domestically focused, Visa is considered the de facto pre-eminent card payment company in the world. This American multinational financial services company facilitates electronic funds transfers throughout the world. Headquartered in San Francisco, California, it is one of the world's most valuable companies. Visa was founded in 1958 by Bank of America (BofA) as the BankAmericard credit card program. Nearly all Visa transactions worldwide are processed through Visa’s global network, known as Visanet, at one of four secure data centers located in different global locations. These facilities are designed to be heavily guarded against natural disasters, crime and terrorism. Each facility can operate independently of the others and can accommodate up to 30,000 simultaneous transactions requiring up to 100 billion computations every second.