FIIs and DIIs both bought on 109 of 524 sessions since 2024

Four combinations, 524 sessions

The database holds NSE's daily institutional cash-market figures from 10 September 2024 to 21 October 2026: 524 sessions. On each one, foreign institutional investors (FIIs) and domestic institutional investors (DIIs) were either net buyers or net sellers. That gives four possible days, and the split is lopsided.

The typical session is FIIs selling and DIIs absorbing it. In ten of 524 sessions, fewer than one in fifty, neither group was a net buyer.

It was not always this way

The share of "both buy" days was 24.5% of sessions in 2025 and 20.2% in 2026, against 10.4% in the last months of 2024. The share of FII-sell/DII-buy days fell from 74.0% in 2024 to 69.7% in 2026, the gap being taken up by the "both buy" days. Within 2026, the pattern is monthly rather than constant. March had no FII buying day at all; August had 11. The month-by-month table lays out each month.

What the Nifty 50 did on each type of day

Joining the flow dates to the Nifty 50's daily closes (the database's latest Nifty close is 19 October, so 21 October is excluded here), the same-day change looks like this:

On days when both groups bought, the index rose on nearly two sessions in three. On the nine days when both sold, it rose twice. Everything in between was slightly negative on average.

This is a description of coincident numbers, and it should be read that way. Institutional net buying is itself influenced by the day's price move: a falling market can bring in buy orders, and a rising one can bring in selling. The figures say nothing about which came first, and nothing about the following day. Compare the earlier check of whether FII selling moves the Nifty and the daily-move table across 518 sessions.

October 2026 so far

October has been unusually one-sided on the FII side: of 13 recorded sessions, FIIs bought on two and DIIs on 12. Only one of the 13 was a "both buy" day, 21 October, with FII net +₹1,022 crore and DII net +₹1,614 crore. The details are in the post on thirteen sessions to 21 October.

How to use this

• The base rate for any given session is "FIIs net sell, DIIs net buy". A day that breaks it is rarer, but 109 such days in 524 means one in five.
• The sample is only about two years, and the DII data from this period reflects strong monthly SIP inflows. It cannot be extended before September 2024 here.
• Nothing in the table is a signal to act on. A 64% hit rate on 108 same-day observations is a fact about the past two years.

Daily and monthly tables with the underlying figures are on the FII/DII data page. Figures are as of 21 October 2026.