Bitcoin Cash is a cryptocurrency that is a fork of Bitcoin. Bitcoin Cash is a spin-off or altcoin that was created in 2017. In November 2018, Bitcoin Cash split further into two cryptocurrencies: Bitcoin Cash and Bitcoin SV. ## **History** Since its inception, Bitcoin users had maintained a common set of rules for the cryptocurrency. On 21 July 2017, bitcoin miners locked-in a software upgrade referred to as Bitcoin Improvement Proposal (BIP) 91, which meant that the Segregated Witness upgrade would activate at block 477,120. Segwit controversially would enable second layer solutions on Bitcoin such as the Lightning Network. A key difference of opinion between Bitcoin users was over the running of nodes. Bitcoin supporters wanted to keep blocks small so that nodes could be operated with fewer resources, while some large block supporters find it acceptable that (due to large block sizes), nodes might only be run by universities, private companies and nonprofits. A group of Bitcoin activists, developers, and China-based miners were unhappy with Bitcoin's proposed SegWit improvement plans meant to increase Bitcoin's capacity; these stakeholders pushed forward alternative plans which would increase the block size limit to eight megabytes through a hard fork. Supporters of a block size increase were more committed to an on-chain medium of exchange function. In June 2017, hardware manufacturer Bitmain, described the would-be hard fork with the increased block size as a "contingency plan", should the Bitcoin community decide to fork implementing SegWit. The first implementation of the software was proposed under the name Bitcoin ABC at a conference that month. In July 2017, mining pool ViaBTC proposed the name Bitcoin Cash. In July 2017 Roger Ver and others stated they felt that adopting BIP 91 (that would later activate SegWit) favored people who wanted to treat Bitcoin as a digital investment rather than as a transactional currency. The fork that created Bitcoin Cash took effect on 1 August 2017. In relation to Bitcoin it is characterized variously as a spin-off, a strand, a product of a hard fork, an offshoot, a clone, a second version, or an altcoin. A Hong Kong newspaper likened this to a new version of word processing software saying: Bitcoin cash is like a new version of Microsoft Word, which generates documents that can no longer be opened via the older versions. At the time of the fork anyone owning bitcoin came into possession of the same number of Bitcoin Cash units. The technical difference between Bitcoin Cash and Bitcoin (at the time of the fork) is that Bitcoin Cash allows larger blocks in its blockchain than Bitcoin which enables it to process more transactions per second. Bitcoin Cash was the first of the Bitcoin forks, in which software-development teams modified the original Bitcoin computer code and released coins with “Bitcoin" in their names, with "the goal of creating money out of thin air". On 1 August 2017 Bitcoin Cash began trading at about $240, while Bitcoin traded at about $2,700. On 20 December 2017 it reached an intraday high of $4,355.62 and then fell 88% to $519.12 on 23 August 2018. In 2018 Bitcoin Core developer Cory Fields found a bug in the Bitcoin ABC software that would have allowed an attacker to create a block causing a chain split. Fields notified the development team about it, and the bug was fixed. In November 2020, there was a second contested hard fork where the leading node implementation, BitcoinABC, created BCHA (now dubbed "eCash" or "XEC").