Stocks making the biggest move premarket: AAPL, NIO, GILD, TEVA, BMY & more

Check out the companies making headlines before the bell:

Apple – Apple is expected to introduce new iPhones at an event to be held at the Apple campus in Cupertino, California at 1:00 p.m. ET.

NIO – NIO will begin trading today on the New York Stock Exchange after the Chinese electric car startup priced its initial public offering at $6.25 per share. That was at the low end of the projected range of $6.25-$8.25 per share, and gives NIO a value of $6.4 billion.

Gilead Sciences – Gilead saw upbeat results for an experimental rheumatoid arthritis drug in a phase 3 study.

Teva Pharmaceutical – Teva will delay launching a generic version of British drug maker Indivior's opioid addiction drug, pending resolution of a U.S. court case involving Indivior and generic drug maker Dr Reddy's Laboratories.

Bristol-Myers Squibb – Bristol-Myers Squibb said its experimental plaque psoriasis drug showed promising results in a mid-stage trial, helping reduce the severity of the disease.

NXP Semiconductor – NXP shares are under pressure, after executives of the Dutch chip maker gave a strategic update. That follows the collapse of the company's proposed merger with Qualcomm. The company had not held quarterly conference calls with analysts

Boeing – The jet maker delivered 48 of its Boeing 737 aircraft in August, a rebound from the 29 it delivered in July. The July total was one of its lowest in years, impacted by supplier delays.

e.l.f. Beauty – e.l.f. is under pressure from activist investor Marathon Partners, according to the Wall Street Journal. The paper cites a draft of a letter that will be sent to the cosmetics retailer's chief executive, pushing for e.l.f. to either sell itself or refocus on core operations. Marathon owns about 8.5 percent of the company's outstanding shares.

Verizon – Verizon will launch next-generation 5G service in October in four cities – Houston, Indianapolis, Los Angeles and Sacramento. Rival AT&T had said earlier in the week that it planned to launch 5G service in a handful of cities sometime this year.

Wells Fargo – The bank's plan to reimburse customers who had bought unnecessary auto insurance was rejected by U.S. regulators, according to Reuters. The bank is said to have been told that it must do more to make sure it has located and compensated every affected driver.

Tiffany – Tiffany was upgraded to "outperform" from "perform" at Oppenheimer, which cites valuation. The luxury goods retailer's stock has fallen more than eight percent over the past month.

Nielsen Holdings – The provider of TV ratings has expanded its strategic review to include the possibility of a full sale of the company. Reuters had earlier reported that the company was being pressured to look at a possible sale by activist investor Elliott Management.

WellCare Health Plans – WellCare will join the S&P 500 prior to the open of trading next Monday, September 17. The managed care services company will replace, XL Group, which is being acquired by property and casualty insurer AXA.

Prudential Financial – Chief Executive Office John Strangfeld will retire as CEO of the financial services company on November 30, to be replaced by international division chief operating officer Charles Lowrey. Strangfeld will serve as executive chairman until April, when Lowrey will assume the chairman's role.