Today's session had briefly looked as if it might build on Wednesday's rebound. Stocks had snapped a three-day losing streak, Europe had rallied sharply, oil had cooled, and Nvidia had done what Nvidia is now expected to do: report numbers so large they make normal corporate earnings look like a neighborhood bake sale. There was also the added excitement of a possible SpaceX IPO, with OpenAI not far behind, giving investors another reason to believe the technology boom still has plenty of fuel. Then Iran re-entered the picture.