Bitcoin, Ethereum ETFs see $313M outflows, ending nine-day inflow streak

U.S. Bitcoin and Ethereum spot ETFs recorded net outflows on April 27, with Bitcoin ETFs losing $263 million and Ethereum ETFs $50.48 million, ending a nine-day inflow streak for Bitcoin ETFs. The Polymarket contract for Bitcoin reaching an all-time high by June 30, 2026, sits at 2.6% YES.

## Market reaction

The Bitcoin all-time high by June 30 market dropped from 3% to 2.6%. The September and December sub-markets also declined slightly, with September at 10.5% YES and December at 17.5% YES. The largest gap in expectations falls between June 30 and September 30, which suggests traders expect potential catalysts during that window.

## Why it matters

Trading volume over the past 24 hours was $917 in actual USDC traded. The June 30 market requires $959 to move the price by 5 points, meaning a single large trade could move odds meaningfully. A 2-point spike appeared in the September market at 3:34 PM, likely from one substantial order.

The ETF outflows broke a sustained inflow pattern and may reflect broader hesitance among institutional allocators. At 3¢, a YES share pays $1 if Bitcoin hits a new all-time high by June 30, a 33x return. That payout only makes sense for traders who expect a sharp price rebound within two months.

## What to watch

Federal Reserve announcements or major corporate Bitcoin adoption news could shift sentiment and odds. Any continuation or reversal of ETF flow trends in the coming days will be the most direct signal of whether this outflow was a one-day event or the start of a longer pattern.

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