Those with a credit card limit of 600,000 are Fortune 500 CEOs. The platinum card of a credit card has a maximum cap of 500,000, while the diamond card and black gold card have a maximum cap of 600,000. They are generally available to private banking customers and Fortune 500 CEOs. They are not accepted by banks at their own invitation. Therefore, those with a credit card limit of 600,000 are Fortune 500 CEOs.