Japan Activist & 5% Filings Tracker (EDINET)

Who is buying into Japanese listed companies — and why?

This actor tracks Japan's large-shareholding reports (the Japanese equivalent of a U.S. SC 13D/13G filing — the "5% rule") straight from EDINET, the Financial Services Agency's official disclosure system, and returns them as clean English structured JSON. No Japanese reading required.

Every time an investor's stake in a Japanese listed company crosses 5%, or changes after that, they must file. Those filings are public, but they are in Japanese, buried in XBRL, and hard to monitor. This actor turns them into a daily, machine-readable feed of who bought whom, how much, and for what stated purpose — including an activist flag when the filing states intent to make important proposals or influence management.

What you get (one record per filing)

{
  "docId": "S100YRH9",
  "submittedAt": "2026-07-29 10:18",
  "filingType": "new",
  "holderNameJa": "ＳＯＭＰＯホールディングス株式会社",
  "holderNameEn": "Sompo Holdings, Inc.",
  "issuerNameJa": "株式会社ティアフォー",
  "issuerSecCode": "593A",
  "holdingRatioPct": 17.49,
  "previousRatioPct": null,
  "ratioChangePct": null,
  "crossedThreshold": true,
  "jointHolders": 1,
  "purposeJa": "自動運転分野における中長期的なシナジー創出のため",
  "purposeCategory": "synergy",
  "purposeEn": "Synergy creation",
  "isPotentialActivist": false,
  "source": "EDINET",
  "edinetDocId": "S100YRH9"
}

• holderNameEn — the holder's official English name, as registered in EDINET (not machine-translated).
• holdingRatioPct / previousRatioPct / ratioChangePct — the stake now, before, and the delta.
• crossedThreshold — true when a holder newly appears above 5% (a fresh position, not an adjustment).
• isPotentialActivist — true when the stated purpose signals activism (important proposals, board/management involvement).

Who it's for

• Individual investors & analysts watching Japanese equities without reading Japanese.
• Newsletter & research writers who need a daily "who's accumulating" feed.
• Quant / AI agent builders who want 5%-rule events as a normalized JSON stream.

Pairs well with

• Japan Corporate Events Monitor — this actor tells you who is accumulating shares; that one tells you what the company itself just disclosed: M&A decisions, board changes, AGM voting results (Japan's 8-K equivalent).
• SEC Insider Trades Tracker (Form 4) — the same idea for the U.S. market: which executives and 10% owners are buying or selling their own company's stock.

Input

Field	Default	Notes
dateFrom	today	First disclosure date (JST), YYYY-MM-DD.
dateTo	dateFrom	Last disclosure date (JST).
docTypes	["350","360"]	350 = new large-shareholding report, 360 = amendment.
secCode	—	Optional issuer stock code filter (e.g. 7203 for Toyota).
maxFilings	0	Cap the run for a cheap test (0 = no limit).
delayMs	500	Politeness delay between EDINET requests.
edinetApiKey	—	Your EDINET API v2 key (free from the FSA). Falls back to EDINET_API_KEY env var.

Getting an EDINET API key

The key is free. Register at the EDINET site (Financial Services Agency) → API section → issue a subscription key. One key, no expiry unless you reissue it. This actor calls only the official documented API (documents.json and document download), never scrapes the web UI.

Notes & limitations

• Purpose text is free-form Japanese; purposeEn is a best-effort category label, with the original always kept in purposeJa.
• Holding ratios are taken as the aggregate across joint holders (the total position).
• Data source: EDINET (FSA). Numeric disclosure data is not copyrighted; usage follows EDINET's terms (API access permitted; high-volume hammering is not — hence the built-in delay).

Run locally

npm install
EDINET_API_KEY=your_key node src/main.js

Local input can be placed in storage/key_value_stores/default/INPUT.json.