Bitcoin’s roughly 22% breakout-week surge, extending its rebound from a mid-August low to about 26%, reached a weekly high of $81,281 before the cryptocurrency fell more than 3% in 24 hours to $77,379 on Friday afternoon in New York. The retreat followed Federal Reserve Chair Kevin Warsh’s first major speech as central-bank head, in which he said he had "more work to do" to combat inflation, potentially reducing expectations for interest-rate cuts. U.S. spot Bitcoin ETFs attracted about $1.14 billion during the latest week and more than $3 billion over nine days, with BlackRock, Fidelity and Grayscale funds recording nine consecutive sessions of net inflows, according to Farside Investors data. The rally initially followed the U.S. Treasury’s Aug. 19 decision to at least double longer-dated liquidity-support buybacks from $2 billion to at least $4 billion per operation beginning Sept. 9, pushing yields lower, weakening the dollar and renewing the debasement trade in Bitcoin, gold and other precious metals. Analysts said forced short covering, contained funding and ETF demand helped drive the move, but its durability depends on sustained spot flows, futures positioning, dollar funding and broader liquidity rather than the Treasury announcement alone.