The stock market, it's often said, doesn't like uncertainty. House Majority Leader Eric Cantor's primary defeat to tea party activist David Brat certainly rattled investors heading into midterm elections.
In the wake of his stunning loss, Cantor, the second-ranking Republican in the House, plans to step down from his post as majority leader, sources told NBC News.
"With the defeat of this very safe incumbent, investors have to wrestle with the unanticipated possibility that not only might the Republicans fail to achieve plurality in the Senate, but also their majority in the House could be threatened," said Sam Stovall, managing director, U.S. equity strategy at S&P Capital IQ.
"It does remind us that politics can surprise you. A little bit of why the market had a pullback today is tied to Cantor's loss here," said Jeffrey Kleintop, chief market strategist at LPL Financial.