Heightened geopolitical tensions in the Middle East following an attack on Iran have led to broad gains in the defense sector during Monday's premarket trading. At the time of writing, RTX Corp (RTX.US) rose nearly 6%, Lockheed Martin (LMT.US) climbed over 5%, L3Harris Technologies, Inc. (LHX.US) advanced more than 3%, and General Dynamics Corp (GD.US) increased over 2%. RTX Corp, one of the world's largest aerospace and defense companies, primarily focuses on missile defense systems and military technology supply. Lockheed Martin, a global security and aerospace firm, has core operations spanning missile and fire control systems, aeronautics, and space sectors. Its leadership in defense equipment positions it to benefit directly from escalating conflicts.