Dow tumbles 430 points on Italy fears and US-China trade tensions

``The Dow fell as much as 430 points -- 1.6% -- on fears about a political crisis in Italy and renewed trade tensions between the United States and China. The index turned negative for the year... The White House also announced Tuesday that it would impose 25% tariffs on $50 billion worth of goods from China and place new limits on Chinese investments in the United States. The move caught investors by surprise. Treasury Secretary Steven Mnuchin said a trade war with China was "on hold" less than 10 days ago.''