Bitcoin core development rebounds in 2025 after multi‑year decline

Bitcoin Core development picked up significantly in 2025, with the software still powering about 78% of all Bitcoin full nodes, according to metrics from Casa’s Jameson Lopp. 

Emails to the Bitcoin Development Mailing List, a central forum for protocol debate, were also up 60% from last year. Lopp said the latest bump was even more surprising, given that mailing list traffic had slumped the previous year after the platform migrated from Linux Foundation servers to Google Groups.

The number of contributors has also continued to grow, with 135 individuals contributing to Bitcoin Core in 2025 compared to approximately 112 the previous year.

Loop says BTC Core developers modified about 285,000 lines in 2026

Despite the increase in activity, overall code changes remained steady, with about 285,000 lines modified during the year versus 276,000 the year before, Lopp reported. In November, Bitcoin Core also wrapped up its first publicly disclosed third-party security audit, led by Quarkslab and funded by Brink, which found no critical or high-severity flaws in the project’s peer-to-peer networking layer.

Moreover, funding for Bitcoin Core development remains steady so far, with VanEck pledging 5% of the profits from its spot Bitcoin ETF to Brink.

Meanwhile, in an October report, 1A1z found that Bitcoin Core had approximately 41 developers, excluding test engineers, researchers, and related protocols such as Lightning Network and Nostr, as well as the closely connected libsecp256k1 library.

The report also compared Web3 developments for comparison. Polkadot, meanwhile, spent $7 million in 2023 on core development with a market cap of merely 1.2 percent of Bitcoin’s. It had boosted its spending to $16.8 million in 2024. Ethereum’s core developer costs: $32.3 million in 2023 and $50 million in 2024, and Bitcoin: around $840 million.

Crypto Fear and Greed Index is at a “neutral” 40

For the first time since October, CoinMarketCap’s Crypto Fear and Greed Index also reached a “neutral” reading on Sunday, signaling a potential easing of investor fear. At 40, the Crypto Fear and Greed Index suggests that investors are neither overly fearful nor bullish. Crypto market confidence declined heavily sometime in November, with the index hitting its lowest reading of 2025, at 10, indicating “extreme fear.”

Similarly, in October, crypto investor confidence in the crypto market had sunk as a major market crash disrupted the bull run. Bitcoin’s value surged above $125,000 days leading up to the dip, eventually sliding to around $80,000. Many altcoins also sank overnight, erasing a significant portion of their value, and the total altcoin market cap (excluding BTC and ETH) plummeted by approximately 33% in just one day. Crypto sentiment has improved from late 2025’s “extreme fear,” but geopolitical risks and lack of retail activity may slow recovery.

The market is still waiting to see how cryptocurrencies will be affected by the US strike on Venezuela. US President Trump announced on Saturday, “The United States of America has successfully carried out a large-scale strike against Venezuela and its leader, President Nicolas Maduro, who has been, along with his wife, captured and flown out of the country.” 

Bitcoin did not exhibit the typical behavior of risk-on assets, which often decline during periods of acute and violent geopolitical or economic stress. While some analysts believe the attack is unlikely to impact the value of Bitcoin significantly, others warn that its true outcome may not become clear until U.S. markets open on Monday.