Ethereum activated its Fusaka upgrade on December 4, 2025, at 9:49 p.m. UTC during Epoch 411392. The upgrade introduces peer data availability sampling (PeerDAS), which increases data throughput for Layer-2 networks by up to 8 times. The technology reduces transaction costs and improves processing speed by fragmenting rollup data into smaller segments.

Strategy has sharply reduced its Bitcoin acquisition activity, falling from 134,000 BTC monthly in 2024 to just 135 BTC in December 2025, according to CryptoQuant analysis. The company has set aside a $1.4 billion cash reserve to cover dividends and debt obligations, providing at least 12 months of financial runway. Bitcoin currently trades near $92,300, closely aligned with estimated production costs.

US Representative Stephen Lynch challenged Federal Reserve Vice Chair Michelle Bowman on December 2, 2025, regarding her earlier remarks about banks engaging with digital assets. The FDIC is expected to release its first stablecoin oversight framework under the GENIUS Act later this month, establishing national standards for bank-linked issuers.

Vanguard Group, the world's second-largest asset manager, will allow trading of cryptocurrency-focused ETFs and mutual funds on its platform starting Tuesday. The firm, which previously deemed digital assets highly volatile, now supports funds investing in Bitcoin, Ether, XRP, and Solana. The decision provides more than 50 million brokerage clients managing over $11 trillion in assets with access to regulated crypto investment vehicles.

Bitcoin dropped below $86,000 on December 1, 2025, marking its steepest decline in recent weeks and erasing prior gains. The downturn triggered more than $400 million in liquidations across leveraged cryptocurrency futures positions. Global digital asset market capitalization contracted approximately 4% to around $3 trillion, according to market data.

Yearn Finance's yETH vault suffered a security breach that resulted in approximately $3 million worth of ETH being stolen. The attacker exploited a smart contract vulnerability to mint excessive tokens and drain the liquidity pool. Other Yearn vaults remained unaffected, with V2 and V3 operations continuing normally.

Tether CEO Paolo Ardoino rejected S&P Global's downgrade of USDT's dollar-peg rating to "weak" on November 26, calling the assessment outdated and incomplete. Ardoino said the agency overlooked Tether's $7 billion excess equity, $184.5 billion in reserves, and $500 million monthly Treasury income. S&P cited increasing allocations to high-risk assets including Bitcoin, precious metals, corporate bonds, and secured loans as the basis for lowering the rating from level 4 to level 5.

Former BitMEX CEO Arthur Hayes stands by his $250,000 Bitcoin price forecast for year-end despite market skepticism. He identifies $80,600 as Bitcoin's recent bottom, with the asset currently trading at $90,864. Hayes cites anticipated Federal Reserve rate cuts and the conclusion of quantitative tightening as key catalysts for the projected 170% rally.

UK regulatory authorities will require cryptocurrency platforms to report all user transactions beginning in 2026. His Majesty's Revenue and Customs will gain automatic access to domestic and international crypto transaction data for the first time, ahead of the 2027 global information exchange under the Cryptoasset Reporting Framework.