Wall Street slightly lower at open

U.S. stocks were slightly lower at the open on Friday as investors took a breather following the Dow Jones Industrial Average's three-day winning streak, which has kept the index firmly above the 20,000 mark. The post-election rally reignited this week following a solid start to earnings season and optimism over President Donald Trump's pro-growth initiatives, catapulting the Dow above the milestone for the first time on Wednesday. Trump's business-friendly decisions since taking office last Fri