Elon Musk became Twitter's largest shareholder last week. 

The Tesla and SpaceX CEO was set to join Twitter's board of directors, but then backed out.

According to a regulatory filing dated Wednesday,...

... the world's richest individual is now offering to buy the company for $43 billion in cash.

Musk tweeted to his 81 million followers on Thursday, "I made an offer."

Musk said he believes Twitter has the potential to be a forum for free speech,...

... but he has doubts about its management's ability to carry out that purpose, and believes it should be "converted" as a private firm.

"Twitter has tremendous potential. I'll take care of it "In the filing, he stated.

"My offer is my best and final offer," Musk concluded, "and if it is not accepted, I will have to reevaluate my position as a shareholder."

President Biden in North Carolina-US