Check out which companies are making headlines before the bell:
Bank of America — The banking giant reported mixed quarterly results, posting earnings per share of 28 cents on revenue of $19.5 billion. Analysts polled by Reuters were looking for 26 cents earnings per share on revenue of $19.86 billion. Bank of America's stock rose about 1.8 percent following the release.
Morgan Stanley — The company's stock rose over 3.5 percent in the premarket after posting better-than-expected quarterly results. Morgan Stanley reported adjusted earnings per share of 43 cents for the previous quarter on revenue of $7.7 billion. Wall Street was expecting the company to report earnings per share of 33 cents on revenue of $7.59 billion.
UnitedHealth — The company's stock gained about 0.5 percent before the bell after posting fourth-quarter earnings per share of $1.40 and revenue of $43.6 billion. Analysts polled by Reuters expected the insurer to report earnings per share of $1.38 on $43.23 billion in revenue. The insurer's quarterly performance was helped by strength in its Optum pharmacy benefit management business.
McDonald's — BTIG upgraded the fast-food giant's stock to "buy" from "neutral," citing McDonald's all-day breakfast, its National Football League partnership and the new "McPick 2" meal deal as potential catalysts for the business moving forward.
Campbell Soup, McCormick — JPMorgan upgraded Campbell's stock to "neutral" from "underweight," citing "increased optimism about margins." The firm also downgraded shares of McCormick to "underweight" from "neutral," because "we think Street estimates and valuation multiples are a bit too lofty."
Michael Kors — Piper Jaffray upgraded the premium handbag maker's shares to "neutral" from "underweight," as it expects improved comparables for the last quarter. "We see overall comps in the negative 6 percent range, anticipate tight expense control, and see the potential for further geographic licenses to come back in house. In addition, we believe the company has continued to execute against its buyback. While we are upgrading KORS to a 'neutral' rating today, we are making no changes to our estimates."
Best Buy, Party City, Sally Beauty Holdings — Morgan Stanley downgraded these three stocks to "equal weight" from "overweight," as "comps have been disappointing for all three which has prevented the stocks to play out as we expected. While we see limited downside for these names, a lack of catalysts and high leverage (for PRTY) moves us to the sidelines."
Freeport-McMoRan — The company's stock rose 5.7 percent in the premarket, as oil and copper prices around the world gained on the heels of Chinese data that were in line with expectations. The second-largest economy in the world grew 6.9 percent in 2015, while U.S. crude prices gained nearly 2 percent.
Netflix — The video streaming giant's stock gained nearly 2 percent before the bell, after falling 7.1 percent last week. Investors will be watching for Netflix's latest quarterly results, which are due Tuesday after the closing bell.
Yahoo — Shares of the tech company rose 2.9 percent in the premarket after a report from Barron's said the stock could gain 35 percent if it sells its core business.
Twitter — The social media platform's website was down intermittently Tuesday morning. "Some users are currently experiencing problems accessing Twitter. We are aware of the issue and are working towards a resolution," the company said.