NEW YORK ( TheStreet) -- Bank stocks are climbing this year, with the S&P 500 Financials Index doubling the return of the S&P 500 Index. But loan quality has yet to improve across the industry.Based on fourth-quarter financial reports, 962 U.S. banks and savings-and-loan institutions have been assigned "recommended" ratings of B-plus or higher by TheStreet Ratings, down from 1,035 in the previous quarter. Banks with ratings of at least A-minus, or "excellent," totaled 509, down from 555 the previous quarter. Out of roughly 8,000 banks and thrifts, 27 received the highest rating of A-plus, unchanged from last quarter. The ratings are based on capital strength, credit quality and earnings.