The Crypto Fear & Greed index (0–100) with its rating, alongside the US stock Fear & Greed score for comparison, current BTC and ETH prices with 24h change, and ~90 days of crypto sentiment history. Pass `?days=N` to size the history. The crypto-sentiment companion to /api/v1/fear-greed (stocks). From x402stock, a market & economic data API (x402, USDC).