US stock futures pared earlier gains and hovered close to the flatline on Wednesday, as investors responded to weaker-than-anticipated economic data and persistent trade tensions. The ADP report revealed that the private sector added merely 37,000 jobs in May, marking the smallest monthly increase in nearly two years and falling significantly short of projections. On Tuesday, the JOLTS report offered an unexpected upside, painting a mixed picture of employment conditions ahead of the key nonfarm payrolls data slated for release on Friday. Meanwhile, market attention is also directed towards the forthcoming ISM Services PMI, scheduled for later today. Trade tensions remain prominent with the implementation of new 50% tariffs on steel and aluminum imports taking effect today. President Donald Trump referred to Chinese President Xi Jinping on social media as "very tough to make a deal with." The two leaders are anticipated to engage in discussions this week. On the corporate side, Nvidia inched up 0.7% in premarket trading, surpassing Microsoft to become the world's most valuable company.