Capital One is buying Discover for $35 billion, in a deal that would bring together two of the nation's biggest lenders and credit card issuers. Virginia-based Capital One was the 12th largest U.S. bank as of the third quarter, with $471.4 billion in total assets and $346 billion in deposits, according to S&P Global. Illinois-based Discover was the 33rd biggest, with $143.4 billion in assets and $104 billion in deposits. Discover has been operating under heightened scrutiny from regulators. Some analysts say the regulatory issues may have prompted the sale. Cre: ABC News