Nikkei 225 Options & Futures Data

Daily positioning data for Japan's benchmark index, built entirely from free official sources and published as a static site. No account, no API key, no paywall.

→ Live site · English pages

Updated every business day by GitHub Actions. The charts below are pulled live from the site, so they show the current data.

What makes this data unusual

Most global traders know the CFTC's Commitments of Traders report, which groups traders into anonymous categories. Japan Exchange Group publishes something different:

• Weekly open interest by named trading participant — Nomura, Goldman Sachs, HSBC, Morgan Stanley MUFG and others, each with their net Nikkei 225 futures position.
• Daily trading volume by participant, published around 17:45 JST.
• Settlement prices including implied volatility for every strike, which makes it possible to estimate gamma exposure from official data alone — no vendor feed required.

There is no direct US equivalent to the first two, and very little written about them in English. See the explainer for how to read the data — including why a firm's persistent short is usually structural rather than a directional view.

What the site publishes

Section	Contents
Nikkei options	Open interest by strike with day-over-day change, put/call ratio history, estimated gamma exposure
Participants	Weekly net open interest per firm, daily volume rankings for large and mini contracts
US markets	CFTC COT positioning with price overlays, CBOE put/call ratios, SPX open interest and gamma, leveraged-ETF assets
Risk monitor	High-yield spreads, breakeven inflation, Sahm rule and other macro stress indicators
Guides	How to read each dataset, using observed examples rather than textbook definitions

Data sources

Everything is public and free.

Data	Source	Published
Open interest by strike	JPX open_interest.xlsx	~20:00 JST
Put/call volume, turnover	JPX whole_day.xlsx	~16:xx JST
Volume by participant	JPX JSON API	~17:45 JST
Open interest by participant	JPX (weekly)	Monday
Settlement prices with IV	JPX rb{YYYYMMDD}.csv	daily
Index prices, ETF data	Yahoo Finance	—
COT positioning	CFTC	Friday (Tuesday data)
Macro indicators	FRED	varies

Raw JPX files are not redistributed; only derived charts and aggregates are published.

How it works

GitHub Actions (weekday afternoons/evenings JST)
  │
  ├─ pipeline/jpx.py       discover and fetch the day's JPX files
  ├─ pipeline/us_data.py   CFTC, CBOE, ETF and options-chain data
  ├─ pipeline/fred.py      macro series with local cache fallback
  │
  └─ pipeline/build.py     compute, chart, and render static HTML
        │
        └─ GitHub Pages

JPX publishes its files at different times of day, so the build keys off a composite of the volume, participant and open-interest dates. If any one of them advances, the site rebuilds — otherwise the run exits without redeploying.

Daily values are appended to data/ and committed back by the workflow, so time series accumulate without any external database.

Running it locally

pip install -r pipeline/requirements.txt
python pipeline/build.py          # writes to site/
FORCE_BUILD=1 python pipeline/build.py   # rebuild even if no new data

Optional environment variables: FRED_API_KEY (falls back to a local cache if absent), ADSENSE_CLIENT / ADSENSE_SLOT (ads are only emitted when both are set).

Repository layout

Path	Purpose
pipeline/jpx.py	JPX file discovery, download and parsing
pipeline/us_data.py	CFTC, CBOE, SPX chain, leveraged ETFs
pipeline/fred.py	FRED series with cache fallback
pipeline/build.py	Calculations, charts, HTML rendering
pipeline/pages.py	Guide article content (JA/EN)
pipeline/tools_page.py	Interactive Plotly page
tools/	Local operational scripts, run from Windows Task Scheduler (see tools/README.md)
data/	Accumulated daily history, committed by CI
site/	Generated output (not tracked)
docs/	Internal planning notes

日本語

日経225オプション・先物の建玉や手口を、JPXなどの公表データから毎営業日自動で集計し、 チャートにして公開しています。行使価格別の建玉分布、Put/Callレシオ、取引参加者別の ポジション、清算値のボラティリティから推定したガンマエクスポージャーなどを扱います。

サイトはこちら。 データの読み方は解説記事にまとめています。

Disclaimer

This project is for informational purposes only. It is not investment advice or a solicitation to trade. Figures labelled as estimates depend on stated assumptions that cannot be verified from public data — the gamma exposure calculation in particular assumes a dealer positioning convention that may not hold. Verify anything you rely on against the original sources.