What happened? Bitcoin Core released v30, which dramatically expands OP_RETURN data limits, changes relay fees, and removes legacy wallet support.
The update removes the 80-byte OP_RETURN cap, raises the default data carrier size to 100,000 bytes (effectively allowing much larger arbitrary data and multiple OP_RETURN outputs), and drops BDB wallet support in favor of descriptor wallets. It also lowers the minimum relay fee and includes security fixes, but the release has split the community and drawn warnings about spam and legal risks.
Who does this affect? Node operators, developers, wallet providers, miners, and everyday Bitcoin users all face immediate choices and consequences.
Node operators must decide whether to upgrade amid controversy and security disclosures, while wallet teams need to migrate away from deprecated systems and update RPCs. Miners and fee-paying users could see changes in transaction composition and fee income as more non-financial data gets stored on-chain, and projects like Ordinals/Runes and data-heavy apps may gain or deepen conflicts with other stakeholders.
Why does this matter? It reshapes on-chain economics and increases short-term market uncertainty, which could influence BTC price action.
If the change fuels more data spam and congestion, legitimate transactions could get pricier and users could be pushed off-chain, hurting adoption and investor sentiment. Traders may respond with consolidation or a pullback—holding support near ~$110k would calm markets, while a failure there could push BTC toward $100k–$105k and deepen the bearish case.