Elon Musk offers to buy Twitter for $43 billion

Elon Musk is offering to buy Twitter for $43 billion, saying the social media company "needs to be transformed as a private company."

The billionaire and founder of electric car maker Tesla, who earlier this month disclosed he owns a 9.2% stake in Twitter, proposed in a regulatory filing on Thursday to buy all of the company for $54.20 per share. 

"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," he said in the filing. "However, since making my investment I now realize the company will neither thrive nor serve this societal imperative in its current form."