Institutional 13f Tracker

Institutional 13F Tracker (SentiSense)

See who owns a stock and how the big money is repositioning. This skill reads institutional ownership from SEC 13F filings through the read-only SentiSense API: the top institutional holders for any ticker, aggregate buying and selling per stock, activist positions, and a full portfolio for any manager (from Berkshire Hathaway to the largest index funds), with quarter-over-quarter change types (new, increased, decreased, sold out) across thousands of filers.

Read-only educational data interface. Output is informational context, never a personalized buy or sell recommendation.

When to Use

Reach for this skill when the question is about institutional ownership or 13F positioning:

• "Who owns $NVDA?" or "top institutional holders of $TSLA"
• "What did Berkshire Hathaway buy and sell last quarter?" (a manager's whole portfolio)
• "Is institutional money accumulating or distributing $AAPL?" (aggregate flows)
• "Which activist funds took new positions this quarter?"
• "How did 13F ownership of $COIN change quarter over quarter?"

This skill pairs naturally with politicians-stock-tracker and insider-trading-tracker: line up 13F accumulation against a congressional purchase or an insider cluster buy on the same ticker. Convergence across sources is the high-conviction read.

Do not use it for order entry, portfolio management, or personalized advice. It has no write, trading, or wallet surface; every endpoint is a GET.

What this data actually is (read before interpreting)

• 13F is quarterly and lagged. Institutions file 13F-HR within 45 days after each quarter end, so the freshest complete data is always the prior quarter. Never present it as real-time positioning.
• Always resolve the quarter first. The quarter-scoped feeds (/flows, /activist, /bonds, /options) need a reportDate. Four endpoints do not: /quarters is the resolver itself, /holders/{ticker} resolves the latest settled quarter for the ticker when you omit it and echoes the one it used, /institutions takes an optional quarter (the value form, 2026Q2, not a reportDate), and /institution/{slugOrCik} takes neither and answers on its own latest quarter. During the 45-day filing window after a quarter ends, the newest entry is pending: true and holds only early filers; use the first quarter with pending: false for complete data. Filter on the flag, never on position. Once the filing window closes, the pending entry is gone and the newest quarter in the array is already complete, so code that skips index 0 on the assumption that the first row is always pending will quote a quarter that is three months staler than what you were served. Checked live on 2026-08-31: the array led with Q2 2026 at pending: false and contained no pending entry at all.
• Filer categories: INDEX_FUND, HEDGE_FUND, ACTIVIST, PENSION, BANK, INSURANCE, MUTUAL_FUND, SOVEREIGN_WEALTH, ENDOWMENT, CONGLOMERATE, OTHER.
• Parent/subsidiary rollups. Large managers file under many CIKs (e.g. Vanguard). A filer profile carries multiCikRollup / childCikCount / childCiks so sub-manager holdings roll up into one portfolio. Report the rollup, not double-counted child rows.
• Report values as given. The dollar field is valueUsd on both sides of the join: on a holder row under /holders/{ticker} and on a holding row inside a manager's portfolio. There is no bare value field on either. It arrives already denominated in US dollars, so quote it as the reported 13F value and do not re-scale or invent a unit. (/bonds names its own total totalValue and /institutional/options splits into callValue / putValue; those are the only other dollar keys in this family.)

Prerequisites

• A free SENTISENSE_API_KEY. Get one at https://app.sentisense.ai/get-api-key. Required on every call; anonymous requests return 401 api_key_required.
• Any HTTP client. Plain curl works, or Python 3.8+ using only the standard library. On macOS python.org installs can raise CERTIFICATE_VERIFY_FAILED: run Install Certificates.command, use the system /usr/bin/python3, or use curl.
• Network access to https://app.sentisense.ai.
• Read-only scope. Every endpoint here is a GET.

Permissions

• Network: HTTPS to app.sentisense.ai only.
• Credentials: SENTISENSE_API_KEY from the environment.
• Shell: none required.
• Files: none.

How to Run

Issue HTTP GET requests to https://app.sentisense.ai, authenticated with the X-SentiSense-API-Key header. Keep the key in the shell environment; never place it in a query string or in user-facing output.

Step 1, always: resolve the quarter. /quarters is a bare array (no envelope). Every other institutional endpoint returns the wrapped envelope { isPreview, previewReason, data }, so unwrap .data first. Unwrapping is not the same as iterating: on /holders/{ticker}, /institution/{slugOrCik}, /institutions and /flows the unwrapped data is an object, and the rows sit one level further in (data.holders, data.holdings, data.institutions, and data.inflows / data.outflows respectively). Check for a list before you loop. A 429 returns a Retry-After header; back off rather than serving a stale value.

Identify your client. Send a User-Agent naming your agent runtime and this skill, for example OpenClaw/1.4 (institutional-13f-tracker) or ClaudeCode/2.1 (institutional-13f-tracker). Substitute your own runtime and version if neither matches. You can also volunteer what your agent is called by adding an agent/<your-agent-name> token inside the same parentheses, as in OpenClaw/1.4 (institutional-13f-tracker; agent/research-desk). All of it is optional, and it is what tells us this skill has real integrations behind it, so it gets prioritized and you get notice before it changes.

# 1) get valid reporting quarters, pick the first with pending=false
curl -s -H "X-SentiSense-API-Key: $SENTISENSE_API_KEY" \
  "https://app.sentisense.ai/api/v1/institutional/quarters"
# -> [{ "value": ..., "label": "Q4 2025", "reportDate": "2025-12-31", "pending": false }, ...]

Endpoints

• GET /api/v1/institutional/quarters : available 13F reporting quarters. Public, bare array of { value, label, reportDate, pending }, newest first. Call this first; use the first pending: false reportDate everywhere below.
• GET /api/v1/institutional/holders/{ticker} : institutional holders for a stock. reportDate is optional here: omit it and the endpoint resolves the latest quarter that actually has holders for this ticker, preferring a settled quarter over a still-filing one, and tells you which one it used in data.reportDate. Pass ?reportDate= from /quarters when you want a specific quarter or are comparing several tickers on one date. The holder list is nested at data.holders (not data directly). Each holder carries filerName, filerCik, filerCategory, entitySlug, cikCount, shares, sharesChange, sharesChangePct, valueUsd (the dollar field, there is no bare value), and changeType (NEW / INCREASED / DECREASED / SOLD_OUT / UNCHANGED). data always carries holderCount (full-quarter count). Paging (recommended): pass limit (1-1000), offset, sortBy, sortDir. A mega-cap can have 5,000+ holders, and notableChanges (holders with a 10%+ change on 10k+ shares) plus returnedCount are returned only when limit is passed. Free: top 5, and free previews omit returnedCount, offset, and notableChanges even when limit is passed (holderCount stays the full-quarter count).
• GET /api/v1/institutional/flows?reportDate= : aggregate institutional buying/selling per ticker. data is an object, not a list, so iterating .data gets you nothing: the two ranked ticker arrays are at data.inflows and data.outflows, alongside data.reportDate, data.filerCount, data.baselineFilerCount and data.isPending. Each row carries ticker, companyName, dollarFlowUsd, netSharesChange, totalSharesBought / totalSharesSold, the position counts (newPositions, increasedPositions, decreasedPositions, soldOutPositions), avgClosePrice, and a per-category net-change breakdown (hedgeFundNetChange, indexFundNetChange, activistNetChange, and one per remaining filer category). Free: top 5.
• GET /api/v1/institutional/activist?reportDate= : activist-filer positions for the quarter (NEW or INCREASED stakes). Free: top 3; PRO: full.
• GET /api/v1/institutional/bonds?reportDate= : convertible bond flows grouped by base ticker, the credit-side leg of the same 13F filings. Free: top 3; PRO: full.
• GET /api/v1/institutional/options?reportDate= : institutional options positions with the call/put breakdown, as disclosed on 13F. Quarterly and end-of-quarter, not live flow. Free: top 3; PRO: full.
• GET /api/v1/institutional/institutions : the filterable universe of tracked filers (use it to find a manager's slug/CIK for the endpoint below). Query category, minAumUsd, sort, quarter. Full list on every tier, and quota-exempt.
• GET /api/v1/institutional/institution/{slugOrCik} : a single manager's profile, summary stats, and current-quarter equity holdings. Resolve by URL slug (Berkshire-Hathaway) or numeric CIK (1067983). Free: profile + top 10 holdings; PRO: full holdings. Holdings include ticker, companyName, shares, valueUsd, changeType, sharesChange, sharesChangePct, portfolioWeight, plus multiCikRollup / childCiks for parent/subsidiary rollups. Returns 404 for an unknown slug or CIK.

Workflows

1. Who owns this stock?

Q=2026-06-30  # first pending:false reportDate from /quarters
curl -s -H "X-SentiSense-API-Key: $SENTISENSE_API_KEY" \
  "https://app.sentisense.ai/api/v1/institutional/holders/NVDA?reportDate=$Q&limit=25"

Read data.holders; lead with the largest holders and the NEW / INCREASED / SOLD_OUT change types and notableChanges (returned because limit is set).

2. A manager's whole portfolio (what did they buy and sell?)

curl -s -H "X-SentiSense-API-Key: $SENTISENSE_API_KEY" \
  "https://app.sentisense.ai/api/v1/institutional/institution/Berkshire-Hathaway"

Summarize new positions, adds, trims, and exits by changeType, and the biggest holdings by portfolioWeight.

3. Aggregate accumulation vs distribution

Q=2026-06-30  # first pending:false reportDate from /quarters
curl -s -H "X-SentiSense-API-Key: $SENTISENSE_API_KEY" \
  "https://app.sentisense.ai/api/v1/institutional/flows?reportDate=$Q"

Read the accumulation side from data.inflows and the distribution side from data.outflows, each already ranked by the size of dollarFlowUsd (negative on the outflow side). A ticker appears on the side its net quarter landed on, never on both, so read the two lists as one board rather than netting them against each other.

4. Activist watch

Q=2026-06-30  # first pending:false reportDate from /quarters
curl -s -H "X-SentiSense-API-Key: $SENTISENSE_API_KEY" \
  "https://app.sentisense.ai/api/v1/institutional/activist?reportDate=$Q"

5. Follow the convergence. When institutional accumulation lines up with a congressional purchase (politicians-stock-tracker) or insider buying (insider-trading-tracker) on the same ticker, that agreement is the read worth surfacing. Cite each source.

Answering well

• Always state the reportDate you are quoting and that 13F data is a quarterly snapshot filed up to 45 days after quarter end.
• Attribute holdings to the filer and category; roll parent/subsidiary CIKs into one manager rather than double-counting.
• Use changeType and sharesChangePct to describe direction; quote valueUsd as the reported 13F value without re-scaling.
• Report only what the API returns. Do not infer positions, prices, or intent that are not in the data, and do not frame any of it as advice.

Going further

Free covers every workflow above at a preview depth (top holders, top-10 portfolio). PRO ($15/mo) lifts the monthly cap (no monthly limit, just a 300/min rate) and returns full holder lists and full manager portfolios, plus congressional, insider, options, and AI-insight data across the SentiSense API. Apply coupon AGENTS26 at checkout for a builder launch discount: https://app.sentisense.ai/pricing?coupon=AGENTS26

Install: npx skills add SentiSenseApp/skills (add -s institutional-13f-tracker for just this skill).

SentiSense is a read-only financial intelligence API. This data is for informational and educational purposes only, not investment advice.