Leading defense and aerospace company Lockheed Martin (NYSE:LMT) has been one of the best-performing stocks over the past four years. But all of a sudden, LMT has been pulling back over the past four trading sessions. The stock is now close to testing its 20-day moving average, which is minor support, so there's a good chance the stock will move lower. The daily chart is signaling very solid support around the $305 – where the stock traded sideways in August before breaking out to new highs. Keep this level on your radar as LMT reports earnings on October 24, 2017.