Altcoin Spot Volume Nears Four Times Bitcoin as ETF Inflows Fade

Glassnode reported altcoin spot trading climbed to nearly four times Bitcoin’s, the highest ratio since September 2025. The analytics firm recorded that 72.5% of tracked altcoins outperformed Bitcoin through Sept. 23, up from 39% during August.

Glassnode described the latest leg of the rally as mostly spot-driven, noting altcoin perpetual open interest barely expanded over the prior 30 days and fewer than half of tracked markets added leveraged positions.

Trading desk flow data showed retail profit-taking as a driver. Wintermute’s Sept. 28 OTC report recorded net Bitcoin selling by retail clients to fund altcoin purchases. Farside Investors’ data listed U.S. spot Bitcoin ETF inflows at $999.0m on Sept. 21, $714.7m on Sept. 22, $346.9m on Sept. 23, $190.7m on Sept. 24 and $134.5m on Sept. 25, totaling about $2.386bn over five sessions and averaging roughly $477m per day.

On-chain metrics from Glassnode showed the Bitcoin spot cumulative volume delta fell 86.5% to $17.3m, perpetual futures delta stood at negative $261.5m, and futures open interest remained near $38.9bn. The share of Bitcoin supply in profit rose to 74% from 69.3% a week earlier, and the realized profit-to-loss ratio increased about 79.6% to 1.4. Ethereum-focused ETFs attracted $602.8m over the same period; Bitcoin products accounted for roughly 80% of combined BTC and ETH ETF inflows.

CryptoQuant calculations put the altcoin market excluding Bitcoin up about $371bn, or 45%, since June. The firm found 87% of Binance-listed altcoins trading above their 200-day moving averages, compared with roughly 20% in August. Altcoin deposits to exchanges reached the highest levels since October 2025, with weekly average deposit transactions above 22,700 on Binance, about 8,300 on Coinbase and roughly 32,000 across other venues.

DeFiLlama reported the stablecoin market capitalization near $306.4bn, a 0.89% increase over 30 days. Glassnode noted the combination of rising altcoin prices and modest stablecoin growth as consistent with rotation among existing holders rather than a surge of fresh stablecoin liquidity.

On the macro front, the Federal Reserve raised its policy rate range to 3.75%–4.00% on Sept. 16. The 10-year Treasury yield touched about 5.23% on Sept. 25 and Brent crude moved above $107 on Sept. 28. Wintermute named oil prices, rates and the possibility of another Fed hike as external risks to the current pattern of capital shifting from Bitcoin into higher-beta altcoins.

Wintermute identified $82,500 as the level that capped Bitcoin’s previous range and outlined scenarios traders are watching: holding between $82,500 and about $87,000 with continued positive ETF flows could allow profit recycling into altcoins, while a clean break above $87,000 would create another pool of profits. Glassnode placed the next major Bitcoin resistance around $95,000 to $97,000. Both Glassnode and Wintermute reported that similar breadth expansions have often preceded flat or negative weeks in past cases.

Market participants will monitor upcoming ETF inflows and price action around the cited Bitcoin levels to see whether buyers continue to absorb coins sold to fund altcoin purchases.