Elon Musk offers to buy Twitter outright for whopping $43 billion price tag, says company needs to be transformed into platform that respects free speech

Elon Musk, Tesla and SpaceX CEO, has offered to buy all of Twitter for $43 billion, according to a Thursday morning Securities and Exchange Commission filing.

The news comes just days after Musk declined to join the company's board of directors after having purchased a 9% stake in the company.

What are the details?

Musk on Thursday announced that he would be willing to pay $54.20 per share — a 54% premium over the stock's price prior to Musk's acquisition of his stake in the company.

Musk in a statement said that he believes the social media company has incredible potential — which he believes he can unlock as its sole, private owner.

"I invested in Twitter as I believe in its potential to be the platform for free speech around the globe, and I believe free speech is a societal imperative for a functioning democracy," Musk wrote in a letter included in the SEC filing.

"As a result, I am offering to buy 100% of Twitter for $54.20 per share in cash, a 54% premium over the day before I began investing in Twitter and a 38% premium over the day before my investment was publicly announced," he continued. "My offer is my best and final offer, and if it is not accepted, I would need to reconsider my position as a shareholder."

"Twitter," he added, "has extraordinary potential. I will unlock it."

What has the company said?

Twitter said that it would "carefully review the proposal" in response to Musk's bid.

"The Twitter Board of Directors will carefully review the proposal to determine the course of action that it believes is in the best interest of the Company and all Twitter stockholders," the company said in a statement on the move.

Following the announcement, Thursday's pre-market trading of Twitter stock was up approximately 11%.

Anything else?

Wedbush Securities analyst Daniel Ives told CNBC on Thursday morning that he believes there is little chance that Twitter would reject Musk's offer.

"This puts Twitter’s back against the wall ... there’s really no way that Twitter in my opinion could reject this," he said.