Ethereum Fusaka Upgrade Live — PeerDAS and Bigger Blob Capacity Begin Scaling Rollups

Published: 2025-12-04 12:23:57 |

Ethereum’s Fusaka upgrade has gone live on mainnet and begins a new twice-yearly hard-fork cadence aimed at scaling rollups. The upgrade activates PeerDAS (Peer Data Availability Sampling), allowing validators to sample smaller parts of blobs instead of downloading full blobs, which reduces duplicate transmissions and bandwidth use. Fusaka also formalises a “blob-parameters-only” (BPO) schedule to raise blob capacity without full hard forks. Blob capacity is scheduled to increase in two BPO steps: around Dec. 17 (from 6/9 to 10/15 blobs per block) and around Jan. 7 (to 14/21 blobs per block). Core developers and contributors, including Vitalik Buterin and Preston Van Loon, say this implements long-standing sharding and data-availability goals and should ease data bottlenecks for layer-2 rollups. Early signals include lower gas prices and smaller mempools; the upgrade is intended to improve L2 throughput and lower per-transaction data costs while preserving decentralisation and home staking viability. For traders: expect potential downward pressure on short-term gas fees and improved capacity for rollup activity, which may increase L2 usage and longer-term network utility for ETH.

Bullish

The Fusaka upgrade materially improves data-availability and capacity for layer-2 rollups by activating PeerDAS and enabling scheduled increases in blob capacity without full hard forks. These changes directly target rollup throughput and per-transaction data costs — core constraints that have limited scaling. Short-term effects: reduced gas fees and smaller mempools as immediate capacity and efficiency improvements are observed, which can lower transaction costs and encourage more on-chain activity. That typically supports stronger network utility for ETH and demand for blockspace, which is bullish for ETH over the medium term. Longer-term effects: as rollups adopt the new space and throughput increases, Ethereum’s utility and fee market dynamics should improve, supporting higher ETH demand for settlement and staking. Risks that temper the outlook include implementation bugs, slower-than-expected rollup adoption, or macro-driven market sell-offs; these could mute price upside. Overall, technical improvement to scaling and lower friction for L2s is a positive catalyst for ETH.