In 2018, as the development of new technologies encountered bottlenecks, people began to realize that blockchain was not a panacea. Thus, the industry embarked on a massive process of de-bubbling, and the iconic event of this "crypto winter" was the hash war triggered by the Bitcoin Cash fork.

This story begins after Bitcoin’s first fork, when Bitcoin split into two versions: BTC and BCH. Although BCH became independent, its development was maintained by multiple teams, including Bitcoin ABC, Bitcoin Unlimited, Bitprim, Nchain, Bitcrust, ElectrumX, Parity, and Bitcoin XT. This laid the groundwork for the subsequent second fork.

By 2018, disagreements arose again when planning Bitcoin Cash’s future, leading to the formation of two major factions. One was the Bitcoin ABC faction, represented by Jihan Wu, the key figure behind Bitcoin’s first fork. They believed that a pure payment-focused approach was no longer suitable and that Bitcoin Cash should evolve into a foundational public chain like Ethereum, expanding its use cases and enhancing competitiveness.

The other faction was Bitcoin SV, represented by Dr. Craig Wright (CSW), an early Bitcoin contributor. They insisted that Bitcoin Cash should remain true to Satoshi Nakamoto’s original vision, focusing solely on transactions and increasing the block size to 128MB.

Neither side could convince the other, leading to incompatible consensus protocols. A date was set for the second fork, where hash power would determine who inherited the Bitcoin Cash name—the winner would become the main chain, and the loser would be phased out.

Tensions were high even during the preparation phase. Half an hour before the official BCH fork, the ABC faction mobilized Bitcoin’s hash power, causing the BCH hash rate of Bitcoin.com’s mining pool to surge by 1,593.09%, equivalent to multiple supercomputers combined, reaching 4,081.03 PH/s. This surpassed the SV faction’s Coingeek mining pool, ranking first.

At 01:52 on November 16, 2018, after the last common BCH block was mined, CSW tweeted, "Game on." Jihan Wu retweeted Jiang Zhuo’s response: "Congratulations! After this new block, there will be no more troublemakers in the BCH community!"

The hash war began, with the rule that whichever side could mine significantly more blocks than the other would win.

The ABC faction quickly gained an advantage, mining two blocks in just 14 minutes, while the SV faction also mined its first block. However, the situation soon became one-sided, with the ABC faction leading by six blocks within two hours. Analysts had previously stated that a six-block lead would essentially mean victory in the hash war.

Facing this, CSW emphasized on social media, "The hash race is a marathon, not a sprint. Never assume victory too early." But in the end, the war concluded with the ABC faction, led by Jihan Wu, emerging victorious, while the SV faction split off to form its own chain.

In the end, there were no real winners. The entire cryptocurrency market capitalization halved again after this war, accelerating the de-bubbling of the blockchain industry and laying a solid foundation for the eventual entry of international giants.