"Once we start seeing free-flowing oil again," Wall Street will set the foundation for its rebound, argues Kevin Mahn. That said, he says "I'm surprised markets haven't pulled back even more," a "helpful" sign for stock market strength. Kevin talks about key defense and nuclear power-centric stocks he likes, from L3Harris (LHX) and Kratos (KTOS) to Huntington Ingalls Industries (HII).