Check out which companies are making headlines before the bell:
Snap — Analysts at Jefferies downgraded the social media company's stock to "hold" from "buy," with analysts noting that "fundamental execution needs to be shown before we can be more positive on the name."
Pandora — Morgan Stanley downgraded the music streaming service to "equal weight" from "overweight," noting that "growing ad revenue in '18 is no longer a given as Pandora faces engagement and monetization challenges."
Caterpillar — Caterpillar shares rose 1.8 percent before the bell after J.P. Morgan upgraded the stock to "overweight" from "neutral." The analysts said in a note they expect Caterpillar's sales to get a boost from the tax bill signed last month.
United Technologies — The Dow component was upgraded to "buy" from "hold" at Goldman Sachs. Analysts said geared turbofan jet engines are reaching a "positive financial second derivative" in their life cycles, which will change the stock's narrative. They also see a 30 percent rally for the stock this year.
Celgene — The biotechnology company agreed to buy private firm Impact Biomedicines for as much as $7 billion. Celgene is interested in Impact Biomedicines' fedratinib, a kinase inhibitor that has shown promise as a potential treatment for a type of blood cancer.
Lululemon — Lululemon raised its fourth-quarter earnings and revenue guidance on the back of strong holiday sales. Shares of the athletics retailer climbed 2.2 percent in the premarket.
Kohl's — Kohl's said its holiday sales rose 6.9 percent year-over-year, surpassing estimates. The company also raised its fiscal 2017 earnings guidance. Kohl's shares surged more than 8 percent.
—CNBC's Michael Bloom and Reuters contributed to this report.