The dollar and U.S. equity-index futures tumbled on news that free-trade advocate Gary Cohn is resigning as President Donald Trump’s top economic adviser. The yen, a haven in times of stress, climbed against the dollar and futures on the S&P 500 Index plunged about 1 percent. The news comes just as the administration prepares to impose steep tariffs on steel and aluminum, which Cohn had opposed. Shortly after the Cohn announcement, the White House said it’s considering clamping down on Chinese investments in the U.S. and imposing tariffs on a broad range of its imports. The protectionist theme promises to take the ... (full story)