Ocado, the British online grocer, has seen a significant surge in its shares after narrowing its first-half losses and raising its full-year guidance. The company reported improvements in cash flow and lifted the annual profit margin guidance for its key warehouse technology division. Despite some key customers rolling out its automated warehouse technology more slowly, the positive financial outlook has reassured investors and prompted a recovery in its previously battered shares. Ocado shares jumped after the profit forecast upgrade, even though the company had previously been labeled as 'underperforming'.