Bitcoin rose above $50,000 on Tuesday for the first time, continuing a rally that has seen it rise nearly 900% since March last year.
Skeptics of the cryptocurrency's ability to go mainstream say it is rarely used for regular transactions and is too volatile to be a reliable store of value or hedge against inflation.
But it has attracted endorsements from business people, celebrities and companies, betting bitcoin will become an alternative to central-bank issued currencies.
Here are some of bitcoin's best-known backers:
The announcement by Musk's electric vehicle company Tesla that it had bought $1.5 billion of bitcoin drove a roughly 20% surge in the cryptocurrency the day it was announced.
Tesla also said it hoped to begin accepting bitcoin as a form of payment in the near future.
The founder of Twitter and payment firm Square Inc is a bitcoin enthusiast and has said he believes the internet will have its own currency.
Square said in October it had bought around 4,709 bitcoins at an aggregate purchase price of $50 million. Twitter said in February it had considered holding bitcoin but had not yet decided.
The rapper has launched a bitcoin development fund with Jack Dorsey that says it will focus on the cryptocurrency's adoption in India and Africa. Jay-Z and Dorsey are to invest 500 bitcoin, currently worth around $24.5 million, in the project.
Tyler and Cameron Winklevoss
The Winklevoss twins, best known for their lawsuit against Mark Zuckerberg over the founding of Facebook Inc, were early bitcoin investors and first said they put money into it in 2012. They established bitcoin exchange Gemini in 2015.
Paul Tudor Jones
The fund manager said in May 2020 there was a case for bitcoin as a "store of value" and that he had more than 1% of his assets invested in the cryptocurrency.
The billionaire investor said in a television interview in November 2020 that he had put money into bitcoin, saying it could outperform gold as a store of value.
The payments giant caused a bitcoin surge in October 2020 when it said customers could buy, sell and hold the cyrptocurrency - and other virtual coins - using its online wallets.
Novogratz, who used to run hedge funds for investment giant Fortress, is chief executive of Galaxy Investment Partners, one of the most prominent firms focused on investing in bitcoin, ethereum and other cyrptocurrencies.
The investment manager, who had a brief stint at the White House as head of communications for Donald Trump, announced at the start of this year that his firm had launched a bitcoin fund.