Recent insider activity at Cummins Inc. (CMI) has raised questions among investors about the future direction of the stock. Sharon Barner, the company's vice president and chief administrative officer, recently sold 4,780 shares at an average price of $300.35 per share, as per a SEC filing on Aug 19. Does this signal a concern about the company's prospects and should you reevaluate your position in the stock?Cummins' Performance and ValuationCummins has had a good run on the bourses, with the stock up 26% y ...