Call cc.etf_flows — Real-time Bitcoin/crypto ETF inflow and outflow data tracking institutional positioning (GBTC, IBIT, FBTC, etc). 60-min cache. Purpose: Real-time Bitcoin/crypto ETF inflow and outflow data tracking institutional positioning (GBTC, IBIT, FBTC, etc). 60-min cache. Behavior: READ-ONLY. Does not place orders, move funds, or mutate your exchange account. Responses may be cached (~3600s). Auth: X-Api-Key or x402 payment proof (X-PAYMENT / __x_payment). Anonymous unauthenticated calls receive HTTP 402 with payment accepts. Cost: $0.002 USDC per successful call (x402 Base USDC pay-per-use or prepaid X-Api-Key balance). Linked Connect keys are free. This is billing, not a side effect. Rate limit: 30/min (per API key). Tier: standard. Returns: Per-ETF daily flow in USD with cumulative totals, showing institutional demand/supply dynamics. Guidelines: Use for research / signal context. Pair with cc.agent_strategy (paper) before any live order. Do not invent fills from this data alone. Tags: etf, institutional, flows, bitcoin, blackrock, grayscale.