Letter to Brian Moynihan, Chairman and CEO of Bank of America, Jaime Diamon, Chairman and CEO of JPMorgan Chase & Co., Michael Corbat, CEO of Citigroup Inc., Michael Roberts, President and CEO of HSBC America Holdings Inc., Torry Berntsen, CEO of Standard Chartered Bank, Robert McCann, Chairman of UBS Americas Inc., and Charles William Scharf, CEO and President of Wells Fargo and Company - Wyden Launches Investigation Into Halkbank Scandal