Take a look at some of the biggest movers in the premarket:

Berkshire Hathaway (BRK.B) – Berkshire reported record annual profit in 2021, helped in large part by its investment in Apple (AAPL). Berkshire also bought back a record $27 billion in stock last year, but the pace of buybacks slowed during the fourth quarter. Berkshire Class “B” shares fell 1% in the premarket.

BP (BP) – BP shares tumbled 7.1% in the premarket after saying it would sell its nearly 20% stake in Russia’s state-controlled oil producer Rosneft following Russia’s invasion of Ukraine.

First Horizon (FHN) – First Horizon shares surged 32.3% in premarket trading after the bank agreed to be acquired by Toronto-Dominion (TD) in an all-cash deal worth $25 per share or $13.4 billion. The move will help Toronto-Dominion expand its presence in the southeastern part of the U.S.

Renewable Energy (REGI) – The maker of renewable energy fuels agreed to be acquired by Chevron (CVX) for $61.50 per share, compared to the Friday close of $43.81. Renewable Energy shares soared 36.5% in the premarket.

Starbucks (SBUX) – Workers at a Starbucks café in Mesa, Arizona voted to unionize, becoming the third Starbucks location in the U.S. to do so. Starbucks slid 1% in premarket action.

Zendesk (ZEN) – The customer service platform operator ended its deal to buy SurveyMonkey parent Momentive Global (MNTV) after Zendesk shareholders rejected the proposed transaction on Friday. That follows objections to the all-stock deal by activist investor Jana Partners as well as skepticism about the deal’s benefits by Wall Street analysts. Momentive slid 2.4% in premarket action while Zendesk rose 0.4%.

Northrop Grumman (NOC), Raytheon Technologies (RTX), General Dynamics (GD) – These and other defense stocks surged in the premarket in the aftermath of Russia’s invasion of Ukraine and the pledge by European Union countries to spend more on defense. Northrop Grumman added 5%, Raytheon Technologies rallied 6% and General Dynamics gained 5.4%.

Healthcare Trust of America (HTA) – The health-care-centered real estate investment trust agreed to combine with rival Healthcare Realty (HR) in a deal with an implied value of $35.08 per share. Healthcare Trust slid 5% in the premarket, while Healthcare Realty tumbled 9.2%.

PulteGroup (PHM), Toll Brothers (TOL) – The home builders received double upgrades to “buy” from “underperform” at Bank of America Securities. The firm notes underperformance by home builders in 2022 despite strong earnings and guidance and feels the risk/reward profile is now favorable. PulteGroup rose 1.1% in the premarket, while Toll Brothers added 1%.

Nielsen (NLSN) – The company best known for TV ratings saw its stock rally 7.6% in the premarket after reporting adjusted quarterly earnings of 46 cents per share, 10 cents above estimates, and also issuing an upbeat full-year forecast. The company also announced a $1 billion share repurchase program.