Trump can try to talk down the U.S. dollar all he wants. The fact is the USD is appreciating based not only on factors largely outside of the U.S. president's control, but also because of the president's actual policies, not tweets. As Reuters reports "actions speak louder than words" and the appreciation in the U.S. dollar is largely a product of Trump's own making. Passing the tax bill encourages multinational corporations to move money back to the U.S. therefore buying U.S. dollars. The larger deficit and economic improvement from tax cuts is also leading to