Big Bank Stocks Stumble After Earnings Missteps

What You Need To Know

• Wells Fargo headed for its worst earnings-day drop Friday in more than three years after its net interest income missed estimates.
• Citigroup is among the 10 worst performers in the S&P, sinking as much as 3.6%.
• Bank of America, Goldman Sachs and Morgan Stanley will be in focus early next week.