Check out the companies making headlines before the bell:

SunTrust, BB&T – BB&T is combining with SunTrust in a $66 billion merger of equals. SunTrust shareholders will get just under 1.3 BB&T shares for each share they now own, valuing SunTrust at $62.85 per share, a seven percent premium to yesterday's close.

Twitter – Twitter reported adjusted quarterly profit of 31 cents per share, 6 cents a share above estimates. Revenue also came in above forecasts. Monthly average user metrics was as expected. Twitter also expects revenue for the current quarter of $715 million to $775 million, compared to the consensus estimate of $765 million.

Dunkin' Brands – The restaurant operator beat estimates by 3 cents a share, with quarterly earnings of 64 cents per share. Revenue missed estimates, however, and U.S. comparable sales were flat compared to a consensus Refinitiv estimate of a 1.6 percent gain. Separately, Dunkin' increased its quarterly dividend to 37.5 cents per share from the prior 34.75 cents.

Cardinal Health – The pharmaceutical distributor earned an adjusted $1.29 per share for its latest quarter, beating estimates by 20 cents a share. Revenue also beat estimates, and Cardinal Health also raised its full-year forecast.

Tapestry – The parent of Coach and Kate Spade reported adjusted quarterly profit of $1.07 per share, 4 cents a share short of estimates. Revenue also missed forecasts and Tapestry cut its full-year forecast due to a slowing global economy.

Yum Brands – The operator of KFC, Taco Bell, and Pizza hut missed estimates on both the top and bottom lines for its latest quarter, but did register better-than-expected increases in comparable-store sales.

Chipotle Mexican Grill – Chipotle reported adjusted quarterly profit of $1.72 per share, beating the consensus estimate of $1.37 a share. The restaurant chain's revenue also beat Wall Street forecasts. Chipotle's comparable-restaurant sales were up 6.1 percent, compared to the 4.5 percent increase that analysts had been expecting. Chipotle benefited from increased customer traffic during the quarter and a spike in online orders.

CSX – CSX raised its quarterly dividend to 24 cents per share from 22 cents. The rail operator pays its next dividend on March 15 to shareholders of record on February 28.

iRobot – iRobot reported quarterly earnings of 88 cents per share, well above the consensus estimate of 50 cents a share. The maker of Roomba robotic vacuum cleaners also saw revenue top Wall Street forecasts, and issued better-than-expected guidance.

GoPro – GoPro beat estimates by 4 cents a share, with adjusted quarterly profit of 30 cents per share. The high definition camera maker's revenue also beat estimates, helped by cost-cutting as well as strong demand for its least expensive cameras.

FireEye – FireEye topped Street forecasts by a penny a share, with adjusted quarterly profit of 6 cents per share. The cybersecurity software maker also saw revenue beat estimates. FireEye also warned that it expected a loss for the current quarter, surprising analysts who had been forecasting a profit.

Sonos – Sonos reported quarterly earnings of 55 cents per share, 14 cents a share above consensus estimates. The maker of wireless speakers also saw revenue beat forecasts, but it also said it is seeing higher inventory levels than it prefers. Separately, Sonos said CFO Michael Gianetto will retire later this year.

Sanofi – Sanofi posted better-thanexpected profit for its latest quarter, and said new drug launches would help push profits higher over the full year.

General Motors – GM released details of an incentive plan for the head of its Cruise autonomous driving unit, Dan Ammann, that provides incentives to develop technology and commercialization strategies and could lead the way to an eventual initial public offering for the unit.

Prudential Financial – Prudential reported lower-than-expected quarterly earnings, driven by losses in its life insurance unit and a drop in asset management income. Prudential earned $2.44 per share for the fourth quarter, compared to a consensus estimate of $2.78 a share.

MetLife – MetLife earned an adjusted $1.35 per share for the fourth quarter, 7 cents a share above estimates. The insurer's revenue came in below Wall Street forecasts, however, on weakness in Asia, Europe, the Middle East, and Africa.

Guess – Jefferies upgraded the apparel maker's stock to "buy" from "hold," noting a valuation discount to its peers and to its own history. Jefferies also pointed to Guess as one of the few retailers with opportunity for sales growth and margin expansion.