Aerospace and defense stock Lockheed Martin Corp (NYSE:LMT) is in the midst of a downtrend, with losses stacking up after the company missed revenue expectations in late October. Shares were last seen 0.8% lower at $485.15, and are pacing for their 15th loss in 20 sessions. The equity has shaved its year-to-date gain to just 6.8% after erasing 17.2% this quarter, but the silver lining is that this drawdown presents a unique buying opportunity, according to historical trends.Per Schaeffer's Senior Quantitati ...