Bundles of stolen credit card numbers continue to be a longstanding product in underground hacking forums. In the U.S., stolen credit card data associated with the Visa and MasterCard brands are $4 each. American Express and Discover run about $7 to $8 each. The most prized cards, according to the study, are stolen credit card numbers connected to account holders in Europe and Asia, which run as high as $28 each. The most useful stolen data must be able to be encoded directly to the magnetic stripe on a fraudulent card. Like any business, buying in bulk can significantly reduce the cost of each card.