A trader works on the floor of the New York Stock Exchange (NYSE).

Check out which companies are making headlines before the bell:

Darden Restaurants – The Olive Garden parent earned an adjusted 73 cents per share for its second quarter, three cents a share above estimates. Revenue also beat forecasts and Darden raised its full-year forecast.

Navistar – The truck maker reported fourth-quarter profit of $1.36 per share, well above consensus estimates of 64 cents a share. Revenue also beat forecasts, and Navistar CEO Troy Clarke called 2017 a "breakthrough year."

FactSet – The provider of financial market information beat estimates by 6 cents a share, with adjusted quarterly profit of $2.04. Revenue did fall slightly below estimates, but CEO Phil Snow said FactSet is making meaningful progress in integrating recent acquisition and is entering the new year with strong earnings growth.

Walmart – Citi upgraded the retail giant to "buy" from "neutral," saying it made a mistake "sitting on the sidelines" this year. Citi said it now believes there's more upside to come for the stock, especially considering that stocks like Costco and Home Depot are trading at premiums to Walmart.

General Motors – The automaker's stock was upgraded to "outperform" from "sector perform" at RBC Capital Markets, which said it doesn't expect North American profitability will be down as much in 2018 as previously forecast.

Apple — Apple was downgraded to "neutral" from "buy" at Nomura/Instinet, which believes gains related to iPhone X upgrades have largely been realized and priced into the stock.

Michael Kors – The luxury goods seller was rated "buy" in new coverage at Needham, which praises the company's turnaround moves and said they could lead to upside earnings guidance.

Chicago Bridge & Iron – CB&I agreed to be bought by McDermott International in an all-stock transaction worth about $6 billion. The two companies provide construction and engineering services for the oil and gas industries.

MetLife — MetLife is under scrutiny by regulators in both Massachusetts and New York, after the insurance company said last week that it had not paid pensions to thousands of retirees. MetLife did say that the group missing out on payments represent less than five percent of those who receive some type of benefit from its retirement business, and that it was committed to fixing the issue.

Cars.com — Activist investor Starboard Value now has a 9.9 percent stake in the online auto marketplace operator, according to a Securities and Exchange Commission (SEC) filing. Starboard believes the stock is undervalued and that it can boost its profit margins, according to The Wall Street Journal. Cars.com was spun off from Tegna, the company formerly known as Gannett.

Roku — An SEC filing revealed that Morgan Stanley has a passive 5.1 percent stake in the maker of streaming media devices.

Extended Stay America – Extended Stay named chief financial officer Jonathan Halyard as its Chief Executive Officer, effective January 1. The hotel operator's current CEO Gerry Lopez will transition to the role of Senior Advisor and remain in that position until March 18, 2018.

Altria — Altria was upgraded to "buy" from "hold" at Berenberg, which said the tobacco producer will benefit from tax changes contained in the bill to be voted on by Congress this week.

Express Scripts – The pharmacy benefits management company authorized an increase in the number of shares that may be repurchased under its buyback program. An additional 45 million shares have been added to the program, bringing the total authorization to 375 million shares.