Looking into the current session, Cigna Inc. (NYSE:CI) shares are trading at $315.58, after a 0.29% decrease. Over the past month, the stock decreased by 8.19%, but over the past year, it actually increased by 7.03%. With questionable short-term performance like this, and great long-term performance, long-term shareholders might want to start looking into the company’s price-to-earnings ratio. A Look at Cigna P/E Relative to Its CompetitorsThe P/E ratio is used by long-term shareholders to assess the company’s market performance against aggregate market data, historical earnings, and the indus…