Musk offers to buy Twitter, social media platform valued at $43 billion

Billionaire entrepreneur Elon Musk has offered to buy all of Twitter at a price that values the social media platform at more than $43 billion. Musk called the offer his "best and final," and said if it was not accepted he would have to "reconsider my position as a shareholder."

He made the offer in a regulatory filing Thursday.

"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," wrote the Tesla CEO in a letter to the company's board chair.

Last week, he bought a 9% stake in Twitter, making him the platform's largest shareholder. 

His filing Thursday continued: "However, since making my investment I now realize the company will neither thrive nor serve this societal imperative in its current form. Twitter needs to be transformed as a private company."

"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. My offer is my best and final offer and if it is not accepted, I would need to reconsider my position as a shareholder."

Musk is the CEO of the pioneering electric vehicle company Tesla. His personal worth is valued at about $259 billion. 

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