Following is a list of the top 10 credit card issuers in the United States ranked by purchase volume. American Express (or Amex) is the largest credit card lender in the U.S. with over $692 billion in credit card payments. As of May 23, 2017, the company had a market capitalization of $69 billion.

Top 10 Credit Card Issuers

Rank Issuer Purchase Volume (US$b), 2015
1 American Express $692.07
2 Chase $541.88
3 Bank of America $297.27
4 Citibank $227.97
5 Capital One $210.33
6 Discover $118.44
7 Wells Fargo $108.83
8 U.S. Bancorp $107.86
9 Barclays $65.43
10 Synchrony $42.20
11 USAA $38.86

 Top Issuers of U.S. general purpose credit cards

Rank Issuer Outstandings (US$b), 2015
1 Chase $130.2
2 Bank of America $99.8
3 American Express $98.3
4 Capital One $82.0
5 Citi $81.8
6 Discover $57.9
7 Wells Fargo $35.4
8 U.S. Bank $34.1
9 Barclays $23.0
10 USAA $18.5

 Number of Credit Cards in Circulation

There are approx. 640 million credit cards in circulation in the United States from the four leading credit card networks.

Rank Credit Card Network Cards in circulation, 2015 Market share
1 Visa 329 million 51.8%
2 MasterCard 192 million 30.2%
3 American Express 58 million 9.1%
4 Discover 57 million 9.0%

 Purchase Transactions Worldwide

Rank Brand US$ billion, 2015 Market share
1 Visa $126.1 56%
2 MasterCard $59.7 26%
3 UnionPay $29.0 13%
4 American Express $7.3 3%
5 JCB $2.8 1%
6 Diners/Discover $2.2 1%

Note: Purchase transactions include commercial and consumer credit, debit and prepaid cards.

 Top Credit Card Issuers in China

Rank Issuer Outstandings (US$b), 2014
1 ICBC $59.6
2 China Construction Bank $53.5
3 Bank of China $43.6
4 Agricultural Bank of China $36.3
5 China Merchants Bank $35.7
6 Bank of Communications $27.4
7 China Minsheng $27.4

Top Credit Card Lenders in Brazil

Itau Unibanco
Banco do Brasil
Banco Bradesco
Banco Santander
Caixa Economica Federal
HSBC Brazil
Alelo Brasil
Citibank Brazil
Votorantim
Banco BMG
Banrisul
Banco Pan (formerly PanAmericano)