Nikkei 225 Options Data

Nikkei 225 closed at 68,309 (-647). Put/call ratio 2.717 (prev 1.43). Heaviest open interest near spot: call 72,000, put 65,000.

What do these numbers mean? → Put/call ratio ・ Gamma exposure ・ Nikkei options field guide

Market Overview

Options Open Interest by Expiry

The nearest three expiries, as published daily by JPX. The back month is sometimes larger than the front. (→ Field guide ・ → SQ explained)

Strikes within ±3,000 yen of the previous close (65,309–71,309). Nearest 3 expiries published daily by JPX. Change is day-over-day.

Left: Open Interest (green = largest per expiry) / Right: DoD Change (increase = green, decrease = red)

Open Interest Distribution by Strike

Strikes with heavy open interest often act as reference levels ("walls"). The largest open interest in the chain is usually a far out-of-the-money legacy position, so look near spot. (→ Why) Includes mini options (27,781 contracts) converted to large-equivalent (1/10).

Mini Options OI (Weekly: 10/8 expiry)

Open interest by strike for Nikkei 225 mini options (weekly expiries) — a gauge of short-term battle lines. (→ Field guide)

Gamma Exposure

Dealers who sold options hedge by trading futures. Depending on where the index sits, that hedging can either dampen or amplify moves. The chart below estimates that force by strike, using open interest and the implied volatility in JPX settlement prices. Actual dealer positions are not disclosed, so this is an estimate (assuming dealers are long calls and short puts).

Above spot +1,139, below spot -48 (100M yen). Net: dampening moves (+1,091 per 1% move).

Implied Volatility by Strike

The Nikkei VI compresses the whole surface into one number, so it cannot tell you which side of the market is paying up for protection. JPX publishes implied volatility for every strike in its daily settlement file, so we plot puts below spot and calls above it. Deep in-the-money contracts print a placeholder 1.0%, so only out-of-the-money strikes are used.

At-the-money implied volatility is 23.1%. Ten percent below spot prices at 35.9%, ten percent above at 26.1%.

A steeper left side means downside protection is more expensive. This is the same volatility that feeds our gamma estimates. (→ how to read it)

Futures Volume (large-equivalent comparison)

Mini is 1/10 the notional of the large contract; micro is 1/100. Raw contract counts are not comparable, so a large-equivalent column is shown. (→ Glossary)

Trading Volume by Participant (daily ranking)

Volume only — this says nothing about direction. It shows which firms are active. (→ How to read it)

Trading date: 2026/10/02 (published by JPX at 2026/10/02 17:41). Volume and share by participant. Direction is not disclosed, but it shows who is most active.

Participants by Type (Foreign / Domestic / Online)

JPX names each participant, which only helps if you know the firms. Here they are grouped into foreign brokers, domestic brokers and online brokers (retail order flow), with Nikkei 225 futures and minis combined on a large-contract basis. Positive is net long. Comparing to zero is meaningless — every group carries a structural bias, so compare each to its own normal.

The correlation column shows how often a group’s weekly position change moved with the Nikkei (+1 = always the same direction). Groupings are ours; Japanese joint ventures such as Mitsubishi UFJ Morgan Stanley count as domestic.

Futures Open Interest by Trading Participant (Weekly)

Bars: weekly net open interest per participant (green = net long, red = net short). Gray line: Nikkei 225 (shape only, no scale). Top 12 participants by latest position size. Comparing against zero is useless — compare each firm against its own baseline. (→ How to read it)

As of 2026/09/25 (weekly data published on the first business day of each week; WoW = one-week change in net open interest)

Foreign Investor Flows (Weekly)

Weekly net buying by foreign investors in TSE Prime cash equities, shown as a cumulative line (top) and weekly bars (bottom), from JPX trading-by-investor-type data. Positive = net buying. Latest week (2026-09 W2): -0.27 tn / cumulative since 2021: +18.17 tn yen

Put/Call Ratio Trend

Above 1.0 = puts dominant; below 1.0 = calls dominant. 1.0 is not the neutral line — the measured average is 1.57 for large contracts. (→ Full explanation)

Guides — How to Read This Data

Background on each indicator and how traders actually use it.