Bitcoin Core Development Rises 60% Following Years of Decrease

In 2025, Bitcoin Core’s development activity experienced a remarkable 60% increase, as evidenced by the volume of emails sent to the Bitcoin Development Mailing List. This turnaround ended a prolonged period of diminishing contributions and marked the protocol’s most vigorous development phase since its inception.

Source: X/@lopp

Core contributor Jameson Lopp reported that this uptick was due to 135 distinct developers contributing code modifications that totaled 285,000 lines. In the same year, Bitcoin facilitated the transfer of $4.5 trillion in value, with an average of $144,000 transacted every second, according to estimates from CoinMetrics.

Source: X/@lopp

This development revival occurred amidst ongoing philosophical debates regarding Bitcoin’s fundamental purpose, with various competing proposals surfacing to tackle issues related to blockchain spam.

Simultaneously, Bitcoin’s price climbed back above $92,000 on Monday following a geopolitical upheaval in Venezuela over the weekend, as institutional investments returned to the crypto markets, with $646 million pouring into ETFs on the first trading day of 2026.

Network Metrics Indicate Maturation Despite Price Stability

Bitcoin had the flattest year on record, exhibiting an average daily price change of only -0.02% in 2025, while the blockchain expanded from 626.5 GB to 710.1 GB, reflecting an annual growth rate of 13.3%.

Source: X/@lopp

Interestingly, the network’s UTXO set diminished from 186.3 million to 165.8 million entries, with one net UTXO being removed every 1.5 seconds as efficiency enhancements took effect.

The network hashrate also rose by 32%, increasing from 802 to 1,060 exahash per second, while the number of reachable nodes grew by 18% to 24,298, according to Bitnodes data.

The median upstream bandwidth for reachable nodes dropped by 39% to 6.6 megabits per second, while Bitcoin Core code commits saw a modest increase of just 1% year over year, totaling 2,541, indicating that changes per commit were likely more significant.

Jameson Lopp, who compiled the yearly metrics, pointed out a troubling trend regarding physical security.

“At the beginning of 2025, I anticipated that we would witness an unprecedented rise in wrench attacks, averaging one each week. Regrettably, that prediction became a reality,” he remarked, referring to violent attempts to steal from Bitcoin holders.

At the beginning of 2025 I predicted we’d see an all-time high for wrench attacks, averaging one per week. Unfortunately, that prediction came true. pic.twitter.com/5ptcwxIjzk

— Jameson Lopp (@lopp) December 31, 2025

Adoption Increases as Data Storage Discussions Heat Up

Merchant adoption grew by 53% in 2025, according to BTCmap, likely spurred by Square enabling Bitcoin payments at point-of-sale terminals.

Corporate balance sheets continued to reach new highs, with companies now holding nearly 7% of the Bitcoin supply as institutional accumulation intensified.

Source: X/@lopp

Bitcoin OP_RETURN outputs fell by 47% year over year, attributed to a decline in interest in the Runes protocol launched in 2024.

Source: X/@lopp

Despite this drop, 33 million inscriptions were recorded on the blockchain in 2025, representing a 58% increase from the previous year. However, fee rates remained exceptionally low, with inscriptions collectively paying only $12 million in fees.

33M inscriptions were stored on the Bitcoin blockchain in 2025, an increase of 58% year over year.
However, fee rates were incredibly low and they only ended up paying a total of $12M in fees this year. pic.twitter.com/SxM5hUPNmY

— Jameson Lopp (@lopp) January 1, 2026

The BSV fork saw another 64% decline against Bitcoin in 2025, now valued at a mere 0.02% of the original protocol.

Lightning Network capacity also quietly reached a record high of 5,805 BTC after a period of decline during most of the year, signaling renewed interest in the Layer 2 payment solution.

2025: The Year of Security Audit and Controversial Updates

Bitcoin Core conducted its first public third-party security audit in November after 16 years of operation, with Quarkslab’s 100-man-day assessment revealing no critical vulnerabilities.

Commissioned by the Open Source Technology Improvement Fund and funded by Brink, the audit identified just two low-severity issues across the peer-to-peer layer, mempool, and consensus logic.

A month prior, Bitcoin Core introduced version 30.0, eliminating the 80-byte OP_RETURN limitation, raising the default data carrier size to 100,000 bytes, and permitting multiple OP_RETURN outputs within a single transaction.

Adam Back, CEO of Blockstream, defended the update as incorporating crucial security patches from “200 most skilled people on the planet,” while detractors cautioned about the risks of spam and potential legal repercussions.

Bitcoin proposal to permanently delete Ordinals and NFT-related UTXOs faces developer backlash over fund confiscation and governance precedent concerns.#Bitcoin #Ordinalshttps://t.co/pBiH0t2fGG

— Cryptonews.com (@cryptonews) December 24, 2025

This upgrade led to a migration to Bitcoin Knots, an alternative implementation that grew to account for 28% of network nodes.

In December, a proposal dubbed “The Cat” by developer Claire Ostrom sought to permanently prohibit Ordinals inscriptions and NFTs by marking their dust-sized outputs as unspendable, prompting fellow contributor Greg Maxwell to label it as “outright theft” of millions in funds.

Bitcoin Recovery Following Geopolitical Shock

As the Bitcoin community celebrates this growth, Akshat Siddhant, lead quant analyst at Mudrex, remarked that institutional interest surged significantly following the events in Venezuela.

“If BTC manages to close above $93,700, the momentum could push it toward $100,000, with support emerging near $88,500,” he noted, mentioning that the Fear-Greed Index turned neutral for the first time since October as crypto ETFs attracted new capital.

At the time of this writing, Bitcoin is priced at $92,861, marking a 1.64% increase over the last 24 hours.

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