TheStreet's co-portfolio manager Jim Cramer says DexCom is a poster child for what is both right and wrong with today's market. DexCom, which makes a device to monitor glucose remotely with no finger pricking, is a disruptive technology that is taking the Type One diabetes world by storm. Cramer says the stock has taken a hit when investors stopped paying attention to cash flow positive stocks and started focusing on earnings per share instead. DexCom has added expenses because they are hiring more salespeople, but Cramer expects the device maker to be cash flow positive in 2015. Cramer believes the stock will turnaround next year.