Altcoin Volume Surges Past Four Times Bitcoin's as ETF Inflows Shrink

Altcoin spot volume has surged to nearly four times that of Bitcoin's, according to Glassnode data. This is the highest ratio since September 2025. Wintermute notes that retail clients on its OTC desk sold BTC last week to fund the rotation into altcoins.

The inflows into US spot Bitcoin ETFs have shrunk over five sessions, from $999 million on Sept. 21 to $134.5 million on Sept. 25, a drop of nearly 87%.

Altcoin perpetual open interest barely expanded in the prior 30 days, and fewer than half of tracked markets added positions. Glassnode describes this as mostly spot-driven.

The ratio of altcoins outperforming Bitcoin has reached 72.5%, up from 39% during August's squeeze. Wintermute notes that breadth has stretched to a level where the weeks that came next were flat to negative in more than 80% of comparable cases, with early-cycle periods as the exception.

BTC gains create wealth, which some traders realize and move outward. The process can coexist with a higher BTC price as long as another buyer absorbs the coins being sold.