Bitcoin SV Activated Its Genesis Hard Fork

Bitcoin SV activated its scheduled Genesis hard fork on February 4, 2020, at mainnet block height 620,538. The change replaced several fixed consensus limits with rules intended to give miners more control over network capacity and restored or modified parts of the Bitcoin scripting system.

The activation was consequential because it was not merely a software performance release. Nodes enforcing the Genesis rules could accept blocks and transactions that older software rejected. That made the upgrade a test of coordination among miners, exchanges, infrastructure operators and businesses using BSV, as well as a declaration of the network’s preferred scaling model.

What Genesis changed

The Genesis specification converted the rule restricting blocks to a fixed maximum number of bytes into a configurable consensus rule. Its default maximum acceptable block size became unlimited, with miners expected to agree on and configure operational values themselves.

That wording did not mean hardware, bandwidth or validation capacity had become infinite. It meant the protocol’s default configuration no longer imposed a fixed numeric ceiling. Actual block production and propagation still depended on miner settings, network connectivity, storage, processing capacity and whether other miners would accept a block.

The specification also set the maximum transaction size at 1 gigabyte, removed consensus limits on the number of signature-checking operations per transaction and per megabyte of block space, and changed multiple scripting rules. It restored the specified behavior of OP_RETURN, raised or removed several script limits, and ended special pay-to-script-hash treatment for outputs governed by the new rules.

A UTXO-height mechanism preserved different validation treatment for outputs created before and after activation. That distinction mattered because a transaction could spend outputs originating under both rule sets; the applicable script rules depended partly on the block height at which each spent output had been confirmed.

The brief chain split

Contemporaneous reports placed the first transaction demonstrating incompatibility with the old rules in block 620,539. Once that transaction was confirmed, nodes still enforcing the earlier rules could not follow the updated chain.

An unidentified miner subsequently extended the old-rule chain by one block during February 4. CoinDesk reported that the Bitcoin Association characterized this as an inadvertent result of a miner failing to upgrade rather than an organized attempt to sustain a competing network. Cointelegraph reported that the old branch added only that single block during the observed period.

The episode illustrated an important limitation of hard-fork activation heights: source code can schedule a rule change, but operational consensus still depends on participants running compatible software. A single old-rule block did not establish a durable rival asset, yet it showed that node counts and miner readiness were not perfectly aligned at activation.

Why it mattered to miners and businesses

Genesis moved BSV further toward a model in which miners would negotiate capacity through configuration and economic incentives. Supporters argued that larger blocks and expanded scripting would accommodate payment, data-storage and enterprise applications while increasing the potential importance of transaction fees.

Those were contemporaneous strategic claims, not demonstrated outcomes on February 4, 2020. Removing a fixed ceiling did not prove demand for block space, sustained fee revenue, application adoption or reliable performance at substantially larger scale. It also transferred more responsibility to miners to coordinate settings that would not fragment block acceptance.

This reconstruction makes no price-performance claim. BSV traded continuously across multiple venues without a single universal closing price, and the reviewed protocol records cannot isolate the upgrade’s effect from broader market activity or other BSV-specific news.

Later documentary context

TAAL Distributed Information Technologies, a BSV miner involved in the activation, subsequently recorded the February 4 completion in its annual management discussion and analysis. That later filing corroborates the event but does not convert the company’s expectations about adoption, transaction growth or fee revenue into facts knowable on the activation date.