Twitter shares resumed trading on Monday as the company announced it had accepted Elon Musk's bid to acquire the company. The stock rose 5.9% to $51.79.

Musk earlier this month offered to buy Twitter for $54.20 a share. Twitter said the board has agreed to the deal, valuing the company at about $44 billion.

The social media company had been expected to decline a deal and had adopted a so-called poison pill to fend off a potential hostile takeover. However, Twitter became more receptive to a bid after Musk revealed he secured $46.5 billion in financing.

The company's board met Sunday to discuss Musk's financing plan for his proposed bid, a source close to the situation told CNBC. The board negotiated with Musk into the early hours of Monday, according to The New York Times.

"I think they almost have to" take the deal, CNBC's Jim Cramer said Monday on "Squawk on the Street." Twitter is set to report first-quarter earnings Thursday, and some, including Cramer, expect the company to post disappointing results.