Three independent datasets are simultaneously indicating an early-stage altcoin rotation in May 2026. According to CryptoQuant, the 90-day AltSeason Index has climbed rapidly to 28.6, just above the Bitcoin Season floor of 20. Meanwhile, the share of altcoins in combined BTC and ETH trading volume on Binance has surged from 31% to 49%, nearly matching the two largest assets. Additionally, the CEX Volume Ratio—which excludes the top five assets—shows an increasing altcoin volume trend this year.
Despite these signals, the AltSeason Index remains 47 points below the 75 threshold needed for a genuine alt season. Historical context highlights an anomaly: no prior cycle in this cycle’s peak reached altseason territory; the highest reading in early 2024 was still well below 75. The current reading at 28.6 raises ambiguity—it could mark the beginning of a rotation that finally completes the unfulfilled 2024 peak, or it could repeat the same brief rise without breaching the threshold.
Volume data confirms the rotation’s direction. Binance’s altcoin share approaching parity with BTC and ETH shows capital is moving into altcoins. However, the CEX Volume Ratio sits at approximately 0.3–0.4, far below the 2021 peak above 2.0. Thus, while rotation is real, its magnitude is only about 15–20% of what characterized the last true alt season.
The key confirmation signal would be the AltSeason Index crossing 50 while the CEX Volume Ratio continues rising and Binance altcoin volume share stays above 45%. A denial would occur if the index falls below 20 and volume ratios revert. As it stands, the rotation has begun, but the alt season remains 47 points away.
