Bitcoin fell 1.6% to $76,890 in the 24 hours before the Senate prepared to vote Tuesday afternoon on the Clarity Act, a landmark cryptocurrency regulation proposal. Polymarket data showed the estimated passage probability dropping to 19% from 31% on Monday, despite last-minute efforts by Republican senators to gain Democratic support. Bitcoin remains up 31% since early July but trades 12% below its 2026 opening level. Ethereum declined 1.9% to $2,475 and XRP slipped 0.2% to $1.40. Crypto-exposed public companies also weakened in premarket trading. ARK Invest sold holdings in Coinbase, stablecoin provider (issuer of dollar-linked crypto tokens) Circle Internet Group, Bullish, CoinDesk's parent company, and Bitmine Immersion Technologies, an Ethereum treasury firm. The investment manager also sold more than 322,000 10X Genomics shares worth about $22 million and nearly 38,300 Alphabet shares valued at roughly $12.8 million. ARK bought about 11,000 Meta Platforms shares through its ARKW fund for approximately $7.1 million, while increasing positions in Ionis Pharmaceuticals, Guardant Health, and drone maker AeroVironment. It reduced holdings of Advanced Micro Devices and Amazon. Market observers anticipate additional downward pressure on Bitcoin and related equities if the legislation fails to advance.