Check out which companies are making headlines before the bell:
Twitter — Alphabet's Google unit will not move ahead with a bid to acquire Twitter, and that Walt Disney and Apple were also unlikely to be suitors, according to Recode.
Wal-Mart — The retailer reiterated its prior financial guidance for this year, and said it expected earnings to be flat next year compared with this year and then up 5 percent the following year. The retailer plans to slow new store growth, and added that it is very strong financially and has flexibility and options that competitors do not have. Wal-Mart executives will discuss these matters in detail at today's Investor Day.
Mylan — The drugmaker overcharged Medicaid for its EpiPen over two decades, according to Democratic Senators Ron Wyden of Oregon and Frank Pallone of New Jersey. They say a letter from the Centers for Medicare and Medicaid Services backs their view that the product was incorrectly classified as a generic drug since the fourth quarter of 1997. Mylan said the product has been classified correctly.
Yum Brands — Yum reported adjusted quarterly profit of $1.09 per share, missing estimates by a penny a share. The restaurant operator's revenue also was below forecasts. The parent of KFC, Taco Bell, and Pizza hut also reported a one percent drop in China same-store sales, compared to estimates of a 4.5 percent increase.
L Brands — The Victoria's Secret parent reported a three percent increase in September same-store sales, well above the 0.1 percent increase estimated by analysts surveyed by Thomson Reuters.
Alnylam Pharmaceuticals — The drug company will stop development of a drug designed to treat a genetic condition that can cause heart failure. The action follows negative results from a late-stage study.
Tesla — Goldman Sachs downgraded Tesla to "neutral" from "buy," and lowered its six-month price target to $185 from $240 per share. Goldman sees increased risk for the automaker owing to its deployment of capital for the takeover of SolarCity, and a potential further delay in the launch of the Model 3.
Walgreens Boots Alliance, CVS Health — UBS began coverage on both drugstore operators with "buy" ratings, praising the "integrated approach to care management" practiced by CVS, and the broadness of Walgreens product offerings.
Abercrombie & Fitch — The apparel retailer was downgraded to "sector weight" from "overweight" at KeyBanc, citing a heavier promotional environment.
AT&T — AT&T has struck a multi-year strategic deal with Amazon Web Services, with the two companies collaborating on cloud and networking capabilities.
MetLife — MetLife plans to spin off its U.S. life insurance business to existing shareholders. It had announced earlier this year that it would separate that unit and rename it Brighthouse Financial, but had not yet chosen the method of separation at that time. The news came in a Securities and Exchange Commission filing, and does not necessarily preclude a change to a different option such as an initial public offering.
JD.com — The shares are getting a boost on news that Wal-Mart is nearly doubling its investment in the China-based online retailer to about 10.8 percent. The Wall Street Journal reports that the move also gives Wal-Mart observer status at JD.com's board meetings.
KLA-Tencor, Lam Research — The companies have canceled their planned $10.6 billion merger. The two semiconductor companies pointed to Justice Department opposition to the deal on antitrust grounds.
Deutsche Bank — The German lender has not been in violation of money laundering rules in Russia, according to a Reuters report, which said a German financial watchdog has found no evidence of wrongdoing.
Costco — The warehouse retailer reported a September same-store sales increase of one percent, doubling the Thomson Reuters estimate of a 0.5 percent rise.
BlackBerry — BlackBerry sales executive Alex Thurber told the BBC that a new keyboard-based BlackBerry device will be on the market within six months.
—By CNBC's Peter Schacknow
Questions? Comments? Email us at marketinsider@cnbc.com
Correction: This story has been updated to fix Mylan's ticker (MYL).