US stocks tumble during opening hour of trade, Trump actions weigh

On the first trading day of the week, major US equity indices pulled back sharply in wake of the US President Donald Trump's executive order on Friday to curb travel from seven Islamic countries, which added on to investors’ worries about the potential risk of his protectionist policies.

Apart from this, investors also seemed to have turned cautious ahead of a heavy week in-terms of economic events and releases, including the FOMC meeting and the keenly watched monthly jobs data. 

At the time of writing, the Dow Jones Industrial Average slumped over 130-points and dipped back below 20,000 psychological mark, while the broader S&P 500 Index lost around 19-points to 2,276. Meanwhile, tech-heavy Nasdaq Composite Index lost over 1.0%, or 63-points and broke below 5,600 round figure mark.

A busy week of important economic releases kicked-off on Monday with the release of Personal Income / Spending data and the Fed's preferred inflation gauge - Core PCE Price Index. During the current trading week, investors will also confront plenty of important corporate results that might continue to put investors on the defense-mode and prompt risk-aversion trade amid times of economic and political uncertainty, which tends to dent demand for riskier assets – like equities.