₿₿₿Bitcoin Horizon
Dashboard
Skip to content
  1. Home
  2. ›
  3. Bitcoin Forks

SegWit2x: The Compromise That Failed

The New York Agreement attempted to end the block size war with a corporate compromise, but community resistance killed it.

Era
November 2017
Sections
4 chapters

The New York Agreement

By early 2017, the Bitcoin scaling debate had reached a stalemate. SegWit had been proposed by the Bitcoin Core development team but was being blocked by miners who refused to signal support. Meanwhile, the big-block camp was preparing what would become Bitcoin Cash. Into this deadlock stepped a group of business leaders who believed a compromise was possible.

On May 23, 2017, representatives from over 50 companies met at the Consensus conference in New York and signed the New York Agreement (NYA). The deal was simple: miners would activate SegWit (satisfying the Core developers), and in return, the block size would be doubled to 2 MB within six months (satisfying the big blockers). The signatories controlled approximately 83% of Bitcoin's hash power and included major companies like Coinbase, Bitmain, Blockchain.info, Xapo, and BitPay. On paper, it looked like the scaling war was over.

The NO2X Movement

The New York Agreement was signed without the participation of Bitcoin Core developers, most individual node operators, or the broader community of Bitcoin users. This exclusion proved fatal. A grassroots movement quickly formed under the banner "NO2X" — users changed their Twitter profiles, ran full nodes signaling opposition, and argued that no group of companies had the right to change Bitcoin's consensus rules.

The NO2X movement was philosophically significant because it articulated a principle that would define Bitcoin governance going forward: hash power does not equal authority. Just because miners and businesses could force a fork didn't mean they should. Bitcoin's rules, the movement argued, are determined by the economic majority — the people and businesses that actually use and hold Bitcoin — not by mining companies. This was a direct repudiation of the idea that Bitcoin is governed by miners, and it established the precedent that full node operators are the ultimate arbiters of Bitcoin's protocol rules.

The Cancellation

As the November 2017 activation date approached, it became increasingly clear that SegWit2x would not achieve consensus. The fork lacked replay protection — a technical safeguard that prevents transactions on one chain from being valid on the other. Without it, users risked losing funds on both chains when they made a transaction. Bitcoin Core developers refused to implement the change, and the SegWit2x development team (led by Jeff Garzik) was too small to maintain a credible alternative client.

On November 8, 2017, just days before the planned fork, the organizers posted a message to the SegWit2x mailing list: "Our goal has always been a smooth upgrade for Bitcoin. Although we strongly believe in the need for a larger block size, there is not sufficient consensus at this time." The fork was dead. Bitcoin's price, which had been volatile in the weeks leading up to the potential split, rallied sharply on the news.

Lessons Learned

The SegWit2x saga was a defining moment for Bitcoin governance. It established several precedents that continue to shape the network:

No backroom deals: A group of companies cannot change Bitcoin's rules by signing an agreement, no matter how much hash power they represent. Bitcoin's consensus process is rough, slow, and messy — but that is a feature, not a bug. It makes Bitcoin resistant to capture by any faction.

Users run the network: The NO2X movement demonstrated that ordinary users running full nodes have real power. When the economic majority refuses to upgrade, miners cannot force a hard fork. This is fundamentally different from how most organizations work, where decisions flow top-down.

The first part worked: Ironically, the SegWit activation that was part of the deal succeeded and remains one of Bitcoin's most important upgrades. It enabled the Lightning Network and increased effective block capacity. The failure was only in the "2x" part — the forced block size increase. In hindsight, SegWit2x was the last serious attempt to change Bitcoin through corporate pressure, and its failure cemented Bitcoin's reputation as a protocol that is extraordinarily difficult to alter without broad consensus.

Frequently Asked Questions

SegWit2x was a two-part proposal that emerged from the New York Agreement in May 2017. The first part activated Segregated Witness (SegWit) on the Bitcoin network, which was achieved in August 2017. The second part would have doubled the block size from 1 MB to 2 MB approximately three months later. The "2x" part was cancelled in November 2017 due to overwhelming community opposition.

The New York Agreement (NYA) was a closed-door deal signed on May 23, 2017, by over 50 companies representing approximately 83% of Bitcoin's hash power and a significant portion of the Bitcoin economy. Signatories included Coinbase, Bitmain, Blockchain.info, and many mining pools. The agreement proposed activating SegWit first, followed by a 2 MB block size increase, as a compromise to end the scaling debate.

SegWit2x failed because it lacked consensus from Bitcoin's full node operators, developers, and a vocal segment of the user community. The "NO2X" movement argued that a hard fork should not be forced by a small group of companies, regardless of their hash power. When it became clear that the fork would create a messy chain split without replay protection, the organizers called it off on November 8, 2017, just days before the planned activation.

Related Glossary Terms

Block Reward
The amount of new Bitcoin awarded to miners for successfully adding a block to the blockchain. The reward started at 50 BTC per block and is cut in half approximately every four years through the halving process.
Cold Storage
A method of storing Bitcoin offline, disconnected from the internet, to protect against hacking and theft. Hardware wallets and paper wallets are common forms of cold storage.
Halving
An event that occurs approximately every four years (every 210,000 blocks) where the Bitcoin block reward is cut in half. Halvings reduce the rate of new supply entering the market and have historically preceded major bull runs.
Mining
The process of using computational power to validate transactions and add new blocks to the Bitcoin blockchain. Miners are rewarded with newly minted Bitcoin (the block reward) plus transaction fees.

More Bitcoin Forks

Bitcoin Cash (BCH): The Block Size Fork
August 2017
Bitcoin SV (BSV): Craig Wright's Fork
November 2018
Bitcoin Gold (BTG): ASIC Resistance
October 2017
Minor Forks: Bitcoin Diamond, Private, and More
2017–2018
Soft Forks vs Hard Forks: How Bitcoin Upgrades
2009–present

Related Content

SegWit
Segregated Witness protocol upgrade explained
Technical Evolution
SegWit, Taproot, Lightning, and how Bitcoin upgrades

Interactive Tools

Use these free tools to plan your Bitcoin strategy.

DCA Calculator
Simulate dollar-cost averaging with Power Law projections
Net Worth Tracker
Project your Bitcoin net worth over time
Retirement Planner
Plan your Bitcoin-powered retirement with FIRE levels
Power Law Model
See where Bitcoin sits on its long-term growth curve

Explore Bitcoin's Current Cycle

Use the Power Law model to see where Bitcoin stands relative to historical support and resistance bands.

View Power Law Chart