The credit concerns that have been weighing on Discover Financial Services' valuation multiple are "misplaced" considering the company's return on equity outlook, "stabilizing" credit trends and "very low" unemployment claims, William Blair analyst Robert Napoli tells investors in a research note. The analyst believes credit has been well controlled and that Discover has significant long-term growth opportunities in its core card and student loan businesses. He finds the stock undervalued and current levels and keeps an Outperform rating on the name.