Hi-tech thieves who specialise in card fraud have a credit line in excess of $5bn (£3.35bn), research suggests.
Security firm Symantec calculated the figure to quantify the scale of fraud it found during a year-long look at the net's underground economy.
Credit card numbers were the most popular item on sale and made up 31% of all the goods on offer.
Coming in second were bank details which made up 20% of the items being offered on criminal chat channels.
The $5.3bn figure was reached by multiplying the average amount of fraud perpetrated on a stolen card, $350 (£234), by the many millions Symantec observed being offered for sale.
Similarly, the report said, if hi-tech thieves plundered all the bank accounts offered for sale they could net up to $1.7bn.