Stocks making the biggest moves premarket: Ford, McDonald's, Under Armour, Verizon & more

Check out the companies making headlines before the bell:

McDonald's – McDonald's fired CEO Steve Easterbrook after determining that a consensual relationship with an employee violated company policy. He'll be replaced by McDonald's USA President Chris Kempczinski.

Under Armour – Under Armour said it is the subject of a U.S. accounting probe, confirming an earlier Wall Street Journal report. The investigation is said to center around whether the athletic apparel maker shifted sales from quarter to quarter to improve financial metrics. Separately, Under Armour reported quarterly profit of 23 cents per share, 5 cents a share above estimates. Revenue also beat forecasts. Under Armour cut its full-year revenue outlook, but said its full-year earnings per share would be at the high end of its prior forecast.

Verizon – Verizon was downgraded to "neutral" from "buy" at Nomura Instinet, saying competitor AT&T's new price reduction and a likely response from T-Mobile US could put pressure on Verizon's revenue growth prospects.

Bausch Health – The drugmaker reported better-than-expected revenue for the third quarter and also raised its full-year revenue outlook. Adjusted profit came to $942 million, up 3% from a year earlier.

Ford Motor – United Auto Workers union leadership approved the new tentative labor deal struck with Ford last week. The agreement now goes to the membership for ratification.

Berkshire Hathaway – Berkshire reported quarterly earnings of $3.07 per share, beating the consensus estimate of $2.84 a share. Warren Buffet's firm also saw revenue come in above forecasts. Growth in Berkshire's business lines helped spur the beat, despite a growing cash pile that Buffett has found difficult to deploy.

Fiat Chrysler – Fiat Chrysler and Peugeot parent PSA Groupe are aiming at signing a merger agreement as early as the beginning of December, according to a Reuters report. The two automakers had said last week that they had initiated talks aimed at striking a 50-50 merger deal.

Harley-Davidson – Harley-Davidson was downgraded to "underweight" from "sector weight" at KeyBanc Capital Markets, citing concerns about increased competition for the motorcycle maker.

Papa John's – Papa John's was downgraded to "hold" from "buy" at Jefferies in a valuation call, with Jefferies also citing increased competition not only among pizza chains but among restaurants in general.

Wright Medical – The medical device maker agreed to be acquired by larger rival Stryker Corp. for about $4 billion in cash or $30.75 per share in cash. That represents a nearly 40% premium over Wright's Friday closing price.

First Horizon – First Horizon and fellow regional bank Iberiabank agreed to combine in an all-stock merger of equals. The combined company will operate under the First Horizon name and will be headquartered in Memphis.

Ferrari – The luxury automaker beat estimates on both the top and bottom lines, and raised its full-year outlook as vehicle shipments rose more than 9% during the third quarter.