The Nasdaq 100 closed lower by around 0.1% on Thursday. Investors, meanwhile, focused on some notable insider trades. When insiders sell shares, it could be a preplanned sale, or could indicate their concern in the company’s prospects or that they view the stock as being overpriced. Insider sales should not be taken as the only indicator for making an investment or trading decision. At best, it can lend conviction to a selling decision. Below is a look at a few recent notable insider sales. For more, check out Benzinga’s insider transactions platform. McKessonThe Trade: McKesson Corporation (N…