Heigtened fears of a trade war between China and the US is the short answer. Last night China announced tariffs on 128 products from the US up tp 25 percent. Interestingly most products are imported from Red or Republican states and include soybeans, nuts, pork, wine. This tactic is aimed right at Teump’s base. Products made in Blue states such as Boeing aircraft were untouched. Very smart politics by President Xi.