Credit and prepaid cards issued directly by Discover Financial Services (DFS) generated $118.44 billion in purchase volume at merchants in 2015, up 2.5% over 2014. Cash advances including balance transfers of $9.38 billion dipped 2.2% from 2014. Purchase volume and cash volume combined reached $127.83 billion, up 2.2%. Cash volume accounted for 7.34% of total volume in 2015 compared to 7.67% the prior year. Outstanding credit card debt increased $1.77 billion to $57.90 billion, up 3.1%. Net principal charge-offs grew 2.4% to $1.22 billion. The net principal charge-off rate of 2.22% was d...