Bitcoin Core progresses in 2025 driven by increasing network activity

Bitcoin Core gained popularity in 2025, with a notable increase in development activity. The software, which powers around 78% of the Bitcoin network's full nodes, has seen more contributors become actively involved throughout the year. This dynamic was highlighted by Jameson Lopp, director of security at Casa, who observed community participation clearly increasing.

Bitcoin Core Sees Increase in Contributions

Activity on the Bitcoin development mailing list increased by 60% in 2025 compared to the previous year, driven by higher trading volume. This list, which constitutes a central platform for proposing improvements and coordinating the evolution of the protocol, has rebounded after a 25% drop observed in 2024, illustrating a renewed commitment from the community.

Code activity remained broadly stable, with around 285,000 lines of code added or removed over the year, slightly above the 276,000 recorded in 2024. Participation also strengthened, with 135 contributors who submitted code at the Bitcoin Core repository, compared to 112 the previous year. The number of commits increased by 1%, reaching 2,541, demonstrating a consistent and sustainable pace of development.

Bitcoin Core Security Review and Ongoing Support

This increase in contributions was accompanied by major technical milestones. Bitcoin Core notably underwent its first independent and public security assessment, carried out by Quarkslab with the support of the non-profit organization Brink. This audit, intended to identify possible vulnerabilities, highlighted two minor problems as well as 13 recommendations of an informative nature. None of these presented any real security risk according to Bitcoin Core's classification system.

The magazine, conducted over a period of 100 daysfollowed a rigorous methodology covering the main aspects of the code base:

• In-depth manual inspection of critical components, with particular attention to thread management and transaction validation
• Dynamic testing leveraging tools already integrated into Bitcoin workflows to simulate real-world conditions
• Advanced fuzzing tests aimed at exploring less conventional areas of the code base and detecting possible weaknesses

Funding for Bitcoin Core development has remained stable, with several organizations continuing to provide financial support. In January 2025, VanEck notably reaffirmed its commitment to returning 5% of the profits of its Bitcoin ETF in cash to Brink, thus ensuring sustainable resources for developer initiatives.

On-chain activity reflects network robustness

At the same time, Bitcoin blockchain activity remained strong in 2025. According to estimates from CoinMetricswhich take into account adjustments linked to probable foreign exchange outflows, approximately 4.5 trillion dollars passed through on the network during the year, an average of $144,000 per second.

The network's computing power has also increased, with the hash rate increasing by 32%, from 802 to 1,060 exahashes per second. This development reflects both increasing network adoption and maintaining a high level of security.