Mizuho Financial Group (MFG) is trying to build up its U.S. business by launching a U.S. Bank Holding Company, known as Mizuho Americas, this Friday. 'The U.S. is the most important market in the world,' says Jerry Rizzieri, President and CEO of Mizuho Securities USA. The company has also launched a new digital presence to build brand recognition in the U.S. Separately, Rizzieri commented on recent global events, saying the Brexit doesn't affect Mizuho's day to day operations, but it has created market uncertainty. Officials from Mizuho rang the opening bell at the New York Stock Exchange on Wednesday.