What do participant wise OI, the FII long short ratio and FII and DII data tell me?
The participant file counts open contracts for four groups, Client, DII, FII and Pro, across futures and options, and an FII long to short ratio is only one group's count, not a signal of where the index goes next. The count mixes hedges, arbitrage and spreads, so a ratio can show positioning without showing intent.
Intermediate
Data as of 10 Jun 2026
Reviewed 16 Oct 2026
Trap check
rupeecase.com/q/participant-wise-oi-fii-data
The FII ratio is one group's open contracts, and the same count holds hedges and spreads
How the daily participant file is built and what a ratio from it can and cannot show. A map of the data, not a signal. Source: NSE participant wise open interest file, fao_participant_oi; layout checked by RupeeCase. As of 16 Oct 2026.
NSE publishes a daily file of open contracts by participant group. The groups are Client, the broker's clients; DII, domestic institutions; FII, foreign institutions; and Pro, the members' own proprietary accounts. For each group it gives long and short contracts across index futures, index options and stock contracts. The unit is contracts. The option chain counts open interest in units, so the two cannot be added together without converting one into the other.
An FII long short ratio divides one group's long contracts by its short contracts in a chosen product. It is a snapshot of positions at the close. It moves when the group rolls, hedges or closes a position, not only when it takes a view.
The same totals hold hedges and spreads. An index future bought against a basket of stocks, a call sold against a holding, and a calendar spread all sit in the group's count. The ratio cannot separate them, and the file gives no reason for any position.
The FII and DII cash flow figures are a different series. They report buying and selling by these groups in the cash market, not open contracts in derivatives, so they should not be added to the participant file or read as one number.
The useful test is dated. Take the ratio on each day, take the index return over the period after it, and count the days both ways. A page in the school would show that table and its result. Until it does, the ratio is positioning data, not a forecast.
Before you trade. Derivatives trading carries a high risk of loss. SEBI's study "Profitability of Individual Traders in the Equity Derivatives Segment (FY25 to FY26)" (August 2026) found that 87.7% of individual traders in equity F&O made net losses in FY26, with aggregate net losses of Rs 91,685 crore. Read the SEBI study
What do participant wise OI, the FII long short ratio and FII and DII data tell me?
The participant file counts open contracts for four groups, Client, DII, FII and Pro, across futures and options, and an FII long to short ratio is only one group's count, not a signal of where the index goes next. The count mixes hedges, arbitrage and spreads, so a ratio can show positioning without showing intent. Not shown. The file gives no reason behind a position, so it cannot read intent. Treat the ratio as positioning data until a dated test is on the page.
Scan the code, fillFill one short form, and join my WhatsApp group. Slides, sources, factsheets and the rebalance logs live there, and members join a daily Google Meet with me.
Education only, not investment advice, a research report or a recommendation to buy, sell or hold any security. RupeeCase (QC Alpha Technologies Pvt Ltd) is not registered with SEBI as an investment adviser or research analyst. Contracts and prices shown are for illustration only, come from NSE end of day files at least 30 days old, and are not recommendatory. Derivatives trading carries a high risk of loss.
