Stocks were under assault on multiple fronts in a busy end to the week. Geopolitical threats rose overnight after the U.S. military executed an airstrike against Syria in retaliation to a chemical attack earlier this week. Closer to home, the March jobs number was a big miss as late-season snow snarled weather-sensitive industries. Defense stocks saw some of this biggest gains of the day. Boeing , Lockheed Martin and Raytheon , the maker of the Tomahawk missiles used in the attack on Syria, each moved higher. Twitter was under pressure after defying a U.S. government request for records that could identify anti-Trump users. The social network is challenging that order in court, arguing that attempts to unmask users violates the First Amendment. PriceSmart fell after quarterly earnings and sales missed estimates. Overall revenue climbed 2%, while net warehouse club sales grew 1.8%.