Banking stocks, led by Citigroup (C), surged Friday on a report by Goldman Sachs analysts that offer a mixed outlook for the sector this year. Citi was upgraded to the firm's conviction list buy, from a standard buy rating. Its shares climbed 7.6% to 41.98 late in the trading day, near an 18-month high. SunTrust Banks (STI) was upgraded to buy from neutral. It climbed 1.7% to 29.12. The analysts also reiterated a conviction buy rating on Regions