Morning Movers: Citigroup Gains on Upgrade; Downgrades Sink U.S. Steel, MannKind

One day after the Nasdaq Composite closed at its highest level in 15 years, stocks look set for a lower open. Agence France-Presse/Getty Images Nasdaq Composite futures have fallen 0.2%, while S&P 500 futures have dropped 0.2%. Dow Jones Industrial Average futures have declined 0.2%. Citigroup (C) has gained 0.9% to 53.95 after it was upgraded to [...]