By Alexandra Gibbs–

U.S. stock index futures fluctuated around the flat-line ahead of Tuesday’s open, as markets around the world try for gains after a tumultuous session on Monday.

Around 5:35 a.m. ET, Dow futures slipped 13 points, but indicated a positive open of 16.20 points. The Nasdaq and the S&P 500 futures indicated a flat-to-upbeat start to their respective trading sessions.

The moves in pre-market trade came after U.S. stock markets tumbled deep into the red on Monday, as trade tensions continued to escalate.

Last week, President Donald Trump took to Twitter to threaten another set of tariffs, this time on the European Union. On Friday, the U.S. incumbent warned of a 20 percent tariff on all car imports from the EU, stating that if the bloc refused to remove its duties on U.S. vehicles, then Washington would have no choice but to act.

On Monday, fears reached new highs after reports surfaced that Washington intended to block some Chinese businesses from investing in U.S. technology. Treasury Secretary Steven Mnuchin, however, called the report “fake news” on Twitter.

While markets around the world try to regain some of the ground lost Monday, trade tumult will likely still rattle investors over the course of the day.

On Tuesday, data scheduled for release includes the Philadelphia Fed’s non-manufacturing business outlook survey at 8:30 a.m. ET, followed by the S&P/Case Shiller House Price Index at 9 a.m. ET.

At 10 a.m. ET, consumer confidence and the Richmond Fed survey of manufacturing activity are set to be released, followed by the Dallas Fed’s Texas service sector outlook survey at 10:30 a.m. ET.

In corporate news, FactSet, Lennar, IHS Markit and Sonic are scheduled to publish their latest earnings results.

And two Fed speeches are expected to take place. Dallas Fed President Robert Kaplan will be in Texas at the Greater Houston Partnership’s State of Talent event, while Atlanta Fed President Raphael Bostic will be at the Birmingham Civil Rights Institute in Alabama.