The S&P 500 and the Dow Jones Industrial Average posted their second consecutive day of gains. First Republic Bank ($FRC@US) gained 29 percent after plummeting nearly 50 percent on Monday, and the KBW Bank index rose by 5 percent. Western Alliance ($WAL@US) and PacWest ($PACW@US)each climbed more than 14 percent. On Tuesday, comments from Treasury Secretary Janet Yellen suggested that the government could use emergency powers to shore up banks with uninsured deposits. Recent turmoil in the banking system has analysts speculating whether the Federal Reserve will proceed with an interest rate hike at its meeting on Wednesday.