{"name":"13f-deltas","description":"Tracks what an institutional manager bought and sold each quarter by diffing their 13F filings, e.g. what did Buffett buy this quarter. Diffs the two most recent 13F-HR filings for a manager (by CIK) and returns added (new positions), exited (sold completely), increased (size up), and reduced (size down) buckets with per-position share deltas, dollar deltas, and pct change. Strictly SEC-public 13F-HR data from EDGAR. Use it as a 13F deltas API, institutional holdings change tracker, hedge-fund quarterly trade detector, 13F diff, or a Berkshire + Bridgewater + Citadel + Renaissance position-change feed.","price":"$0.05","method":"POST","input_schema":{"properties":{"cik":{"type":"string","description":"Institutional manager's SEC CIK (e.g. '0001067983' for Berkshire Hathaway). Required — 13F filings are by CIK only, no ticker."},"limit_holdings":{"type":"number","description":"Max positions to include in each bucket (added/exited/increased/reduced). 1-50. Default 20."},"min_change_usd":{"type":"number","description":"Filter out moves smaller than this dollar magnitude. Default 0 (no filter)."}},"required":["cik"]},"input_example":{"cik":"0001067983","limit_holdings":20},"output_example":{"cik":"0001067983","manager_name":"BERKSHIRE HATHAWAY INC","latest_period":"2026-03-31","previous_period":"2025-12-31","summary":{"added_count":3,"exited_count":1,"increased_count":12,"reduced_count":8,"total_value_latest_usd":280000000000,"total_value_previous_usd":270000000000},"added":[{"ticker":"DPZ","cusip":"...","shares":1300000,"value_usd":530000000}],"exited":[{"ticker":"PARA","cusip":"...","shares_previous":50000000,"value_previous_usd":540000000}],"increased":[{"ticker":"OXY","cusip":"...","shares_delta":1000000,"value_delta_usd":60000000,"pct_change":0.02}],"reduced":[{"ticker":"AAPL","cusip":"...","shares_delta":-10000000,"value_delta_usd":-2300000000,"pct_change":-0.01}],"source":"SEC EDGAR (Form 13F-HR)"},"x402_payment_required":true,"x402_facilitator":"https://api.cdp.coinbase.com/platform/v2/x402"}