David Einhorn's Greenlight Capital took new positions in Sprint Nextel and BP during the fourth quarter.

Boeing says it won't kill the 717. Genzyme will enter the S&P 500.

The Dow -- on the back of 3M, GM and GE -- posted a solid triple-digit gain.

Sequoia Capital and Y Combinator have told startups that cutting costs is a priority.

Elon Musk will soon allow Dogecoin to purchase SpaceX merchandise.

The theme park company has opened Guardians of the Galaxy: Cosmic Rewind and not everyone is happy despite the ride getting wonderful reviews.

Aurora is slashing its production capacity as it builds a runway toward positive Ebitda a year from now.