Clean, canonical SEC 13F institutional-holdings data — deduplicated filers, canonical tickers (no CUSIP fragmentation), ownership, crowding, consensus, and fund skill/alpha metrics. The messy part of EDGAR, already solved, over a simple JSON API.
https://qwresearch.com/api/v1Send your key as a header Authorization: Bearer <api_key>, or as ?api_key=<api_key> in the URL. Evaluation endpoints also work without a key; the demo and premium / higher limits require one. Get a free key.
Every endpoint returns JSON. Send your key as a Bearer token, or as ?api_key= in the URL:
curl -H "Authorization: Bearer <api_key>" \
"https://qwresearch.com/api/v1/data/top-filers?limit=5"A sample of what the API returns — real responses from the live data.
/data/top-filers?limit=25The largest 13F filers ranked by portfolio value, with quarter-over-quarter change and skill (alpha) metrics attached.
curl -H "Authorization: Bearer <api_key>" \
"https://qwresearch.com/api/v1/data/top-filers?limit=25"{
"period": "2026-03-31",
"count": 25,
"items": [
{
"cik": "0002012383",
"company_name": "BlackRock, Inc.",
"period_of_report": "2026-03-31",
"total_value_thousands": 5723531457,
"holdings_count": 50651,
"value_change_pct": -3.3,
"annualized_alpha": -0.027409,
"alpha_consistency": 0.0,
"alpha_quarters": 5
}
]
}/institutional/most-held?limit=25The stocks held by the most institutions, with institutional ownership %, total value, and shares — grouped by canonical ticker (no CUSIP fragmentation).
curl -H "Authorization: Bearer <api_key>" \
"https://qwresearch.com/api/v1/institutional/most-held?limit=25"{
"period": "2026-03-31",
"items": [
{
"ticker": "MSFT",
"company_name": "Microsoft Corporation",
"cusip": "594918104",
"total_institutions_holding": 5944,
"institutional_ownership_pct": 71.84,
"total_value_thousands": 1897624733611,
"total_shares_held": 5336395214
}
]
}/stocks/{ticker}/ownershipInstitutional ownership for any stock: % of shares held, number of institutions, total shares, quarter-over-quarter change, and a crowding signal.
curl -H "Authorization: Bearer <api_key>" \
"https://qwresearch.com/api/v1/stocks/AAPL/ownership"{
"ticker": "AAPL",
"company_name": "Apple Inc.",
"period": "2026-03-31",
"institutional_ownership_pct": 63.38,
"total_institutions_holding": 5858,
"total_shares_held": 9309145113,
"company_shares_outstanding": 14687356000,
"signal": "neutral"
}/funds/{cik}/overviewAny fund's profile: AUM, rank, holdings, plus raw price-return alpha and Fama-French "skill" alpha (with t-stat and significance) — the metrics behind our research.
curl -H "Authorization: Bearer <api_key>" \
"https://qwresearch.com/api/v1/funds/0001067983/overview"{
"fund": {
"cik": "0001067983",
"fund_name": "BERKSHIRE HATHAWAY INC",
"aum_usd": 263095703570,
"total_positions": 29,
"aum_rank": 76,
"annualized_alpha": -0.044819,
"alpha_consistency": 44.2,
"ff_alpha_tstat": -0.8557,
"ff_alpha_significant": false,
"skill_badge": "No Clear Edge"
}
}Funds (behavior, sectors, turnover, factor decomposition, hit-rate), stocks (holders, ownership history), institutional flows (top buys/sells, ownership race), crowding & consensus, capital migration, and natural-language /ask endpoints — with a live “try it” playground.
The free tier is self-serve — no email needed. Grab a key and start hitting the API in a minute. For higher limits, bulk exports, or custom datasets, email us.