BIP-110 ‘Anti‑Spam’ Bitcoin Fork Stalls After Two Blocks, Stranded by Difficulty Retarget

Bitcoin’s latest governance skirmish ended where the market usually decides: with hash power. A minority fork enforcing BIP‑110—an “anti‑spam” soft fork to temporarily filter non‑financial data such as Ordinals inscriptions—activated at block 961,632 and then effectively froze. In roughly eight hours, the breakaway chain produced only two blocks before falling far behind the main network.

The core issue wasn’t ideology; it was math. Bitcoin’s difficulty retarget occurs every 2,016 blocks. The minority chain inherited the mainnet’s current difficulty while mustering only a sliver of compute—about 2.53% of recent blocks had signaled for BIP‑110, well under the 55% threshold BIP‑110 sought to meet for activation without splitting. At that pace, blocks arrive hours apart and the next difficulty adjustment sits roughly 350 days away, compared to about two weeks on Bitcoin. Once you fork into that regime with minimal hash, you’re effectively locked into a slow lane that few miners or users will tolerate.

Here’s how the split unfolded. Nodes running BIP‑110 began rejecting any block that didn’t signal support. When AntPool mined a non‑signaling block, Bitcoin accepted it; BIP‑110 nodes rejected it. A miner on the Ocean pool produced the alternative block the minority chain followed. Within hours, the splinter chain trailed the main network by dozens of blocks as Bitcoin continued to produce one roughly every ten minutes. By early Sunday, public commentary crystallized the outcome: about 99.85% of hash power remained with Bitcoin, the BIP‑110 branch had mined only two blocks, and it was already more than 80 blocks behind.

What BIP‑110 proposed is straightforward: a soft fork to temporarily bar embedding images, text, and other non‑financial data in transactions. Supporters argue that inscriptions clog block space and push up fees for everyday payments, creating network spam and legal exposure for hosting arbitrary data. Opponents counter that anyone paying for block space can use it as they choose, and that enshrining content policing in consensus risks undermining Bitcoin’s censorship resistance. Critics have also warned that turning a content dispute into a rule change sets a troubling precedent for future interventions.

The operational hazards didn’t end with liveness. Because both chains validated identical transactions, users faced replay risk: a sale broadcast on the minority chain could be mirrored on Bitcoin, inadvertently transferring real BTC to the same counterparty. Meanwhile, the fork’s mandatory signaling window closes at block 963,647—a height the minority chain won’t approach at its current cadence.

What matters here is the deterrent built into Bitcoin’s game theory. Difficulty inheritance punishes small‑hash splits, converting philosophical disagreements into immediate economic pain: hours‑long block times, no fee revenue to speak of, brittle UX, and severe replay liability. Miners, who live and die by predictability and margins, tend to migrate toward the chain with throughput, liquidity, and tooling. Pools felt that gravity quickly—AntPool stayed with Bitcoin while a single Ocean‑sourced block briefly animated the fork—illustrating how brand, counterparty trust, and treasury risk shape behavior when incentives diverge.

There’s also a social layer that often gets underestimated. Public reactions signaled reputational costs for aligning with minority censorship attempts. Some prominent voices applauded the market’s verdict and criticized BIP‑110 backers for being swayed by polarizing narratives and for hostility toward long‑time contributors. That response, whether one agrees with the tone or not, raises the coordination bar for any future attempt to constrain transaction content at the base layer.

If you care about network hygiene, this episode suggests a path: solutions that don’t require consensus rule changes. Market‑based fee policies, mempool filters at the edge, or opt‑in standards can target spam without fragmenting the chain or jeopardizing neutrality. Conversely, trying to codify content restrictions in consensus invites the exact trap we just saw—hash flight, difficulty lock‑in, and replay hazards—while eroding Bitcoin’s credible neutrality that many users value.

The lesson is less about inscriptions and more about mechanism design. Activation thresholds exist to prevent contentious minority rule changes; difficulty retargeting timelines harden that protection. When only 2.53% of signaling meets a 55% requirement, the fork isn’t just unpopular—it is structurally unworkable. Markets internalized that instantly, and the network moved on.