Crypto rules finalized, Bitcoin retreats, Solana upgrades | Weekly recap

In this week’s edition of the weekly recap, US regulators finalized stablecoin rules under the GENIUS Act, Bitcoin lost ground after a sharp reversal in ETF flows, and Solana activated Alpenglow. Corporate Bitcoin financing, institutional custody deals, and Ethereum’s postponed testnet upgrade also shaped crypto.news coverage for Oct. 18–24. Jan. 18, 2027, is the effective date for the OCC’s final GENIUS Act stablecoin rules. $635.49 million left US spot Bitcoin ETFs on Oct. 22, ending three consecutive inflow sessions. Solana activated Alpenglow on Oct. 21, targeting roughly 150-millisecond finality with its new consensus system.