Twitter Inc. is poised to accept billionaire Elon Musk's "best and final" $43 billion takeover offer, people familiar with the matter told Reuters on Monday.

Earlier in April, the social media company had adopted a "poison pill" to protect itself from Musk's $54.20 per share offer, which followed days after he had disclosed a 9.2% stake.

Musk, a prolific tech entrepreneur, whose net worth is nearly $300 billion according to Forbes, has founded, co-founded or is leading the following companies:

Neuralink - 2016

The brain chip startup aims to connect humans and computers. In July last year, it said it had raised over $200 million from investors including Google Ventures.

SpaceX - 2002

The company designs and manufactures aerospace technology, and aims to land its rockets on Mars before 2030. It was valued at over $100 million, CNBC reported last year.

The Boring - 2017

The underground tunneling company company aims to build hyperloops, an ultra-high-speed ground transportation system for passenger and cargo, to solve big city traffic problems.

Tesla Inc. - 2003

The electric-car maker, which went public in 2010, is valued at more than $1 trillion, more than legacy automakers Ford and General Motors combined. Last year, Musk said the company will probably launch a "Tesla Bot" humanoid robot prototype in 2022, designed for dangerous, repetitive, or boring work that people don't like to do.

PayPal - 1998

The fintech company went public as Holdings Inc. first in 2002, and was bought by eBay Inc for $1.5 billion soon after. It then went public again in 2015.

Stripe Inc. - 2010

The digital payments company was valued at $95 billion in a fundraising round last year. Reuters reported in July 2021 that Stripe hired a law firm in its first major step towards a stock market debut.

Vicarious - 2010

The artificial intelligence and robotics company, which has received over $250 million in funding, also counts Jeff Bezos and Mark Zuckerberg as its investors, according to the Vicarious website.