Bitcoin was invented by Satoshi Nakamoto, who published the invention on 31 October 2008 in a research paper called "Bitcoin: A Peer-to-Peer Electronic Cash System". It was implemented as open source code and released in January 2009. Bitcoin is often called the first cryptocurrency although prior systems existed. Bitcoin is more correctly described as the first decentralized digital currency.
One of the first supporters, adopters, contributor to bitcoin and receiver of the first bitcoin transaction was programmer Hal Finney. Finney downloaded the bitcoin software the day it was released, and received 10 bitcoins from Nakamoto in the world's first bitcoin transaction.
Other early supporters were Wei Dai, creator of bitcoin predecessor b-money, and Nick Szabo, creator of bitcoin predecessor bit gold.
In 2010, an exploit in an early bitcoin client was found that allowed large numbers of bitcoins to be created. The artificially created bitcoins were removed when another chain overtook the bad chain. Based on bitcoin's open source code, other cryptocurrencies started to emerge in 2011. In March 2013, a technical glitch caused a fork in the block chain, with one half of the network adding blocks to one version of the chain and the other half adding to another. For six hours two bitcoin networks operated at the same time, each with its own version of the transaction history. The core developers called for a temporary halt to transactions, sparking a sharp sell-off. Normal operation was restored when the majority of the network downgraded to version 0.7 of the bitcoin software.
In 2013 some mainstream websites began accepting bitcoins. WordPress had started in November 2012, followed by OKCupid in April 2013, TigerDirect and Overstock.com in January 2014, Expedia in June 2014, Newegg and Dell in July 2014, and Microsoft in December 2014. The Electronic Frontier Foundation, a non-profit group, started accepting bitcoins in January 2011, stopped accepting them in June 2011, and began again in May 2013. In May 2013, the Department of Homeland Security seized assets belonging to the Mt. Gox exchange. The U.S. Federal Bureau of Investigation (FBI) shut down the Silk Road website in October 2013.
In October 2013, Chinese internet giant Baidu had allowed clients of website security services to pay with bitcoins. During November 2013, the China-based bitcoin exchange BTC China overtook the Japan-based Mt. Gox and the Europe-based Bitstamp to become the largest bitcoin trading exchange by trade volume. On 19 November 2013, the value of a bitcoin on the Mt. Gox exchange soared to a peak of US$900 after a United States Senate committee hearing was told by the FBI that virtual currencies are a legitimate financial service. On the same day, one bitcoin traded for over RMB¥6780 (US$1,100) in China. On 5 December 2013, the People's Bank of China prohibited Chinese financial institutions from using bitcoins. After the announcement, the value of bitcoins dropped, and Baidu no longer accepted bitcoins for certain services. Buying real-world goods with any virtual currency has been illegal in China since at least 2009. The first bitcoin ATM was installed in October 2013 in Vancouver, British Columbia, Canada. With about 12 million existing bitcoins in November 2013, the new price increased the market cap for bitcoin to at least US$7.2 billion. By 23 November 2013, the total market capitalization of bitcoin exceeded US$10 billion for the first time.
In the U.S., two men were arrested in January 2014 on charges of money-laundering using bitcoins; one was Charlie Shrem, the head of now defunct bitcoin exchange BitInstant and a vice chairman of the Bitcoin Foundation. Shrem allegedly allowed the other arrested party to purchase large quantities of bitcoins for use on black-market websites. In early February 2014, one of the largest bitcoin exchanges, Mt. Gox, suspended withdrawals citing technical issues. By the end of the month, Mt. Gox had filed for bankruptcy protection in Japan amid reports that 744,000 bitcoins had been stolen. Originally a site for trading Magic: The Gathering cards, Mt. Gox had once been the dominant bitcoin exchange but its popularity had waned as users experienced difficulties withdrawing funds.
On 18 June 2014, it was announced that bitcoin payment service provider BitPay would become the new sponsor of St. Petersburg Bowl under a two-year deal, renamed the Bitcoin St. Petersburg Bowl. Bitcoin was to be accepted for ticket and concession sales at the game as part of the sponsorship, and the sponsorship itself was also paid for using bitcoin.
Less than one year after the collapse of Mt. Gox, United Kingdom-based exchange Bitstamp announced that their exchange would be taken offline while they investigate a hack which resulted in about 19,000 bitcoins (equivalent to roughly US$5 million at that time) being stolen from their hot wallet. The exchange remained offline for several days amid speculation that customers had lost their funds. Bitstamp resumed trading on 9 January after increasing security measures and assuring customers that their account balances would not be impacted.
The bitcoin exchange service Coinbase launched the first regulated bitcoin exchange in 25 US states on 26 January 2015. At the time of the announcement, CEO Brian Armstrong stated that Coinbase intends to expand to thirty countries by the end of 2015. A spokesperson for Benjamin M. Lawsky, the superintendent of New York state’s Department of Financial Services, stated that Coinbase is operating without a license in the state of New York. Lawsky is responsible for the development of the so-called 'BitLicense', which companies need to acquire in order to legally operate in New York. In August 2015, it was announced that Barclays would become the first UK high street bank to start accepting bitcoin, with the bank revealing that it plans to allow users to make charitable donations using the currency.