Check out the companies making headlines in midday trading.

Defense stocks — Defense stocks rose as the conflict between Russia and Ukraine continued on Monday and European countries pledged to spend more on defense. Northrop Grumman climbed about 6%, while Raytheon Technologies gained about 2.7%, and General Dynamics added roughly 2%. Lockheed Martin, which was also upgraded to to outperform from peer perform by Wolfe Research, rose more than 4%.

BP — Shares of the oil and gas giant fell more than 5% after the company said it would offload its nearly 20% stake in Russia’s state-controlled oil producer Rosneft. BP CEO Bernard Looney and former exec Bob Dudley are also resigning from Rosneft’s board, effective immediately.

Block — Shares of fintech company Block rose more than 3% after an upgrade to outperform from BMO Capital Markets. The company said investors have an opportunity to pick up shares of Block at a growth-at-a-reasonable-price level after the stock’s pullback.

Tesla — Shares of Tesla rallied 5.5% after Bernstein hiked its price target on the EV stock. “One obvious justification for TSLA’s valuation is its unique growth profile, which stands out, even among tech companies,” analyst Toni Sacconaghi said. However, Sacconaghi kept an underperform rating on the stock and still forecasts significant downside from here.

Renewable Energy Group — Shares of Renewable Energy Group surged about 40% after Chevron said it would buy the biodiesel maker in an all-cash deal valued at $3.15 billion.

First Horizon — Shares of the Memphis-based bank surged nearly 30% following news that the company will be acquired by TD in an all-cash deal worth $13.4 billion, or $25 per share, a move that will allow the Canadian banking giant to expand its footprint in the southeastern part of the U.S.

Healthcare Trust of America — Shares of the health-care-centered real estate investment trust fell more than 4% following news that it will merge with rival Healthcare Realty in a deal with an implied value of $35.08 per share. Healthcare Realty shares dropped more than 10%.

Foot Locker — Shares of the shoe retailer rose more than 5% despite being downgraded to underweight from equal weight at Morgan Stanley. The Wall Street firm said it’s concerned about revenue potential after the company said it would sell fewer Nike products.

Gilead Sciences — Shares of Gilead Sciences dipped about 1.7% after BMO downgraded the stock to market perform from outperform. “We are not negative on the name, but view Gilead as a ‘show me’ story and look to management for further de-risking of assets before we are more constructive,” the firm said.

Lear Corp — The automotive-seating company saw its shares fall more than 5% following a downgrade by Morgan Stanley from overweight to equal eight. The firm said its concerned about Lear’s decelerating growth.

 — CNBC’s Hannah Miao and Maggie Fitzgerald contributed reporting