Some traders are already bracing for a violent Monday, but first they will get through Friday, listening to Fed Chair Janet Yellen for any guidance on whether international risks are serious enough to keep the central bank from raising rates this year.
Greece's debt drama is the most pressing international risk, and it will play out over the weekend, with its parliament voting Friday on the proposed economic overhaul that is being presented to Greece's creditors. The vote would authorize Prime Minister Alexis Tsipras to negotiate with creditors, and the 28 heads of the European union will then meet Sunday.
"The Greeks have confounded conventional wisdom in every single iteration, including the referendum vote. It is absolutely a waiting game, and we'll see what the world looks like on Monday," said Julian Emanuel, UBS equity and derivatives strategist.