Stock futures for the Dow Jones indicated a decline in tech-heavy Nasdaq composite on Monday due to a sharp drop in SpaceX stock. Companies like Amazon, Alphabet, and Nvidia also experienced significant losses. The market sentiment was cautious as tech stocks tumbled, impacting major players in the industry. This news highlights the challenges faced by these companies resulting in a sell-off in their shares. It is indicative of the volatility and uncertainty surrounding the tech sector at the moment.