Bitcoin Cash underwent a contentious hard fork on November 15, 2018, splitting into two competing versions—ABC and SV—after a hash war battle for mining dominance.
Bitcoin Cash experienced a divisive hard fork on November 15, 2018, creating two separate networks after competing developer factions could not reach consensus on protocol changes. The split resulted in BCH ABC supported by major exchanges and BCH SV, with miners engaging in an unprecedented hash war for dominance over the Bitcoin Cash brand and ticker symbol.
Bitcoin ABC proposed enabling canonical transaction ordering, a technical change designed to improve transaction throughput and network efficiency. Bitcoin SV, representing "Satoshi's Vision," advocated increasing the maximum block size from 32 megabytes to 128 megabytes to prioritize raw transaction capacity over other network considerations. These competing visions reflected fundamental disagreements about Bitcoin Cash's development direction and technical roadmap.
The hash war began immediately after the fork as both camps concentrated mining equipment onto their respective chains to establish dominance. Roger Ver, a prominent Bitcoin Cash advocate and Bitcoin.com operator, directed mining pool resources toward ABC to strengthen that chain's security. Craig Wright's camp marshaled significant mining power toward the SV chain, creating a competitive stalemate where computational resources repeatedly switched between competing implementations.
Major cryptocurrency exchanges rapidly chose to recognize ABC as the legitimate Bitcoin Cash continuation, assigning the BCH ticker symbol to the ABC chain. This designation carried profound consequences because it determined which version would retain the $4 billion market capitalization associated with the Bitcoin Cash brand. Traders holding BCH at exchanges holding ABC won the asset outcome, while those positioned on SV chains faced immediate depreciation of holdings valued under the SV ticker.
The entire hash war contest consumed substantial electricity and mining resources estimated at approximately $18 million in expenditures. Both sides maintained high difficulty levels as they competed for block production, raising cumulative costs dramatically above ordinary network maintenance requirements. This efficiency waste illustrated the costs of failed consensus governance when stakeholder groups cannot compromise.
The fork revealed fissures within the Bitcoin Cash community previously obscured by price appreciation. Developers pursuing maximum scale diverged sharply from those emphasizing other properties like transaction speed or network decentralization. These technical disagreements proved irreconcilable through existing governance mechanisms.
By late November 2018, ABC consolidation around the Bitcoin Cash brand appeared decisively established. The SV chain continued operating as a separate cryptocurrency with its own community and development team. This outcome demonstrated that exchange listing decisions and community consensus significantly influence which forked chain retains association with original brand and market value.
Bitcoin Cash's contentious fork established precedent for how competing implementations settle dominance questions through mining competition and exchange coordination.
