On-chain holder metrics (BTC and ETH only)
Retained for the two assets where the realised-cap concept is meaningful (notes §5). Sources: CoinMetrics community API (MVRV, exchange supply and flows, active addresses, hash rate), ultrasound.money (ETH staked, unofficial). Long-term-holder SOPR and realised cap are unavailable in free tiers; an optional Glassnode adapter activates with a key.