Reading
FII/DII Data
Institutions move the index. Learn what FII and DII activity actually signals — cash vs derivatives, index-futures positioning, the long-short ratio — and the mistakes retail traders make with it.
FII (Foreign Institutional Investors) and DII (Domestic Institutional Investors — mutual funds, insurers, banks) are the elephants of the Indian market. Their daily net buying and selling is published, and reading it well gives you a sense of who is providing the bid and who is providing the offer. It won't tell you the next tick, but it frames the medium-term tide.
The two pots: cash vs derivatives
FII/DII data comes in two flavours, and conflating them is the first mistake.
- Cash market — net equity bought or sold in the delivery segment. This is the cleaner "investment" signal. Sustained FII cash selling with DII cash buying is the classic tug-of-war that has defined many Indian markets: foreigners de-risking, domestic funds absorbing.
- Derivatives (F&O) — positions in index futures, stock futures and options. This is faster-moving and more tactical. FII index-futures positioning is the piece most traders watch for directional bias.
The FII index long-short ratio
The single most-watched derivatives number is the FII long-short ratio in index futures — how many long index-futures contracts FIIs hold versus shorts. Read it relative to its own recent range, not as an absolute:
- Ratio high / rising → FIIs are net long index — supportive of upside, or at least not fighting it.
- Ratio low / falling → FIIs are net short index — a cautious-to-bearish tilt that can cap rallies.
- Extreme readings can be contrarian — a very low ratio means a lot of shorts that could fuel a covering rally (see short covering).
How to actually use it
- Trend, not a single day. One day of FII selling is noise. Five sessions of relentless selling against DII buying is a regime — and tells you who's likely to blink first.
- Cash for the tide, futures for the tactics. Use cash flows for the medium-term lean; use the index-futures long-short ratio for the near-term directional bias.
- Pair it with the option chain. FII bias plus the PCR and OI walls gives you both the "who" and the "where".
- Mind expiry. Around monthly expiry, derivatives data is distorted by rollovers — read positioning in the next series, not just the expiring one.
Where retail goes wrong
Three traps: (1) treating one day's number as a trade signal; (2) reading cash and F&O as the same thing; and (3) using absolute figures instead of comparing to the recent range. FII/DII data is context, not a trigger — it tells you the backdrop against which your option-chain and price signals play out.
Track FII/DII activity live
TradePulse publishes daily FII/DII activity — cash and derivatives — alongside the live option chain and AI commentary. Free to start.