Ethereum News Today: Fusaka Upgrade's Success Paves Path for Ethereum's Scalable, Low-Cost Future

Ethereum developers successfully executed the second test of the Fusaka upgrade on the Sepolia testnet on October 14, 2025, following a prior deployment on the Holesky testnet CoinDesk^[1]. This milestone marks a critical step toward the upgrade's mainnet activation, with a final test scheduled on the Hoodi testnet on October 28 CoinDesk^[1]. The Fusaka upgrade introduces PeerDAS (Peer Data Availability Sampling), a protocol enabling validators to verify only portions of transaction data ("blobs") rather than entire sets, reducing bandwidth usage and operational costs for institutional users and layer-2 networks CoinDesk^[1].

The upgrade follows Ethereum's May 2025 Pectra upgrade and is part of a three-phase rollout strategy. Holesky, the first testnet, was deprecated after its role in validating the initial deployment CoinDesk^[1]. Sepolia, widely used for simulating mainnet conditions, was chosen for its reliability in stress-testing upgrades Economic Times^[5]. Hoodi, Ethereum's newest testnet, mirrors mainnet conditions closely and will serve as the final rehearsal before mainnet activation Economic Times^[5]. Developers emphasized that the testnet sequence ensures robust validation of the upgrade's performance and stability Economic Times^[5].

Technical advancements under Fusaka include a gas limit increase from 45 million to 150 million, allowing higher transaction throughput and reduced congestion Crypto.com^[6]. Additionally, the upgrade introduces BPO (Blob Parameter Only) forks to incrementally scale blob capacity. BPO1 will raise the per-block blob target and maximum from 6/9 to 10/15, while BPO2 will further increase them to 14/21 Ethereum Foundation Blog^[2]. These adjustments aim to enhance layer-2 scalability without compromising network security or decentralization Ethereum Foundation Blog^[2].

PeerDAS is central to Fusaka's scalability goals. By enabling partial data sampling, the protocol reduces the computational and storage demands on validators, making it easier for smaller nodes to participate Cointelegraph^[8]. This innovation directly benefits layer-2 rollups like Arbitrum and Optimism, which rely on efficient data availability for cost-effective operations Cointelegraph^[8]. The Ethereum Foundation highlighted that PeerDAS aligns with the network's long-term roadmap to support decentralized finance (DeFi) and application growth while maintaining security Cointelegraph^[8].

The upgrade also includes optimizations to the Ethereum Virtual Machine (EVM), such as the CLZ opcode for efficient bitwise operations and native support for the secp256r1 elliptic curve, which enhances compatibility with Web2 authentication systems Ethereum Foundation Blog^[2]. These changes improve developer flexibility and reduce friction in integrating Ethereum with mainstream hardware and software ecosystems Cointelegraph^[8].

A four-week bug bounty program, offering up to $2 million in rewards, was launched to identify vulnerabilities ahead of the mainnet activation, scheduled for December 3, 2025 Crypto.com^[6]. Developers emphasized that the structured testnet timeline and community-driven audit process reflect Ethereum's commitment to iterative, risk-managed upgrades .

The Fusaka upgrade is anticipated to lower transaction fees and improve user experience, particularly during periods of high network activity Crypto.com^[6]. Institutional interest in Ethereum has grown, with major asset managers like BlackRock and Fidelity increasing ETH exposure, driven by the upgrade's potential to enhance scalability and cost efficiency 99Bitcoins^[7]. Analysts project that the upgrade could catalyze further adoption of layer-2 solutions and staking, potentially boosting ETH demand .