Every evening, market news carries the same pair of numbers. Foreign institutions sold so many crore of shares, and domestic institutions bought so many crore. In October the pattern has been very clear. Over the first 15 trading sessions of the month, up to October 23, FIIs were net sellers of ₹51,466 crore in the cash market while DIIs were net buyers of ₹59,110 crore, which left the combined institutional flow at a net buying of ₹7,644 crore. Investors then ask a natural question. If foreigners are selling so heavily, why has the market not collapsed, and if domestic institutions are buying so strongly, why has the Nifty not recovered? This article explains who FIIs and DIIs are, why they behave differently, who really moves the market, and how a long term investor can use the data without being misled by it.

Who the FIIs and DIIs are

FIIs are foreign institutional investors, which the regulator calls foreign portfolio investors. They include global asset managers, sovereign wealth funds, pension funds and other large investors from outside India who buy and sell Indian shares through the exchanges. DIIs are domestic institutional investors, such as insurance companies, banks, pension funds and the funds run by domestic asset managers. These institutions invest money that comes from Indian households and businesses, for example premiums, contributions and regular monthly savings.

The balance between the two has changed a great deal. In 2025, DII ownership of Indian equities overtook FII ownership for the first time. A report cited in May 2026 put FII ownership at 14.7 percent in April, a 14 year low, and DII ownership at 18.9 percent, a record. Other data providers show slightly different numbers, because they define the groups differently, but all of them show the same direction. Foreign ownership has fallen, and domestic ownership has risen.

What the numbers have looked like

The size of the flows can be large and they can change sign from one day to the next. The table below shows a few sessions from October. The figures are provisional exchange data as reported by market websites, so please check the final figures on the exchange and depository websites before you rely on them.

Three things stand out. First, on most days the two groups are on opposite sides. Second, this is not always so. On October 16, FIIs were net buyers and DIIs were net sellers, and domestic selling more than offset the foreign buying on that day. Third, the month as a whole shows a clear pattern. FIIs were net sellers on 12 of the first 15 sessions, and DIIs were net buyers on 14 of them. On a yearly basis, foreign outflows are very large. Depending on the data source and date, the net FII outflow for 2026 stood at about ₹4.27 lakh crore to ₹4.45 lakh crore by mid October, and by May the foreign selling for the year had already passed the full year total of 2025. At the same time, domestic institutions have bought more than ₹4 lakh crore of shares this year.

Why FIIs sell

Foreign investors decide how much to hold in India by comparing it with other countries and other assets, so their decisions depend on the world as much as on India. When US bond yields rise above 5 percent, as we explained in our article on bond yields, a safe return in dollars competes with Indian shares. When the dollar is strong and the rupee is weak, the dollar value of their Indian holdings falls. When oil prices rise, India pays more for imports, the current account deficit widens and the rupee comes under pressure, as in our article on oil shocks. When valuations look high compared with earnings growth, or when there is geopolitical tension, foreign funds reduce risk. These reasons are mostly outside India's control, and they explain why foreign selling can continue for many weeks even when Indian companies are doing fine. FIIs also concentrate their holdings in large and liquid stocks, such as banks and IT, so their selling tends to show up first in these parts of the market.

Why DIIs buy

Domestic institutions receive money regularly. Insurance premiums, pension contributions and the monthly savings of households arrive every month, and the institutions must invest them. A good part of this money goes to equities, and because it arrives regardless of the market level, domestic buying can continue even when prices fall. Their time horizon is longer, and they do not depend on the exchange rate. This is the structural change in the market. Domestic flows have become large enough to absorb a big part of foreign selling, which is why record foreign outflows in 2026 have not produced a full collapse of the indices. DIIs are not a fixed source of demand, though. As the October 16 data shows, they also sell on some days, and if household savings or market confidence weaken, their buying can slow.

So who really moves the market?

The honest answer has four parts.

The price is set by whoever is on the other side of the marginal trade. On any day, the price moves until the buyers and sellers balance. If FIIs sell more than DIIs buy, prices fall, and if DIIs buy more than FIIs sell, prices rise or hold. This is why the net figure matters more than either number alone. In October so far, the combined net institutional flow has been slightly positive, which is consistent with a market that has been choppy and not in free fall.

Flows are also a result of prices, not only a cause. Foreign investors often sell after prices and the rupee have fallen, and they buy after prices rise, so a flow can be a reaction to the market and not the reason for it. It is easy to read a correlation as a cause, and the truth is usually a mixture of both.

The two groups play different roles. FIIs set much of the tone for the valuations of large companies, for the rupee and for sentiment, since their decisions react to global conditions. DIIs act as a floor. They reduce the depth of falls and the speed of selling, but they do not remove falls. The Nifty is still about 14 to 15 percent below its January peak, even with strong domestic buying, which tells you that a cushion limits a fall and does not prevent it.

Flows are only one factor. Corporate earnings, interest rates, oil prices, the rupee, retail participation and traders in the derivatives market also move prices. A day when FIIs and DIIs both buy can still be a down day if other sellers dominate, and a day when FIIs sell heavily can end higher if earnings news is strong.

What the data cannot tell you

The daily flow data is useful, but it has limits. The figures published each evening are provisional and they can be revised. They cover the cash market, while foreign investors also take large positions in index futures and options, which do not show up in these numbers. FII figures include participation in IPOs, block deals and other large transactions, so a single large deal can distort a day. Different websites use different definitions and sources, which is why the year to date numbers vary. And a flow number says how much was bought or sold, not why. For these reasons, treat the daily data as context for what is happening in the market, and not as a signal to act on.

How a long term investor can use the information

First, use the trend and not the day. A single day of heavy FII selling tells you little, while nine or ten weeks of persistent selling tells you that foreign sentiment is weak for reasons that are probably global. Second, ask why. If the cause is a change in US yields or the oil price, the effect on Indian shares may reverse when those conditions change, and if the cause is a deterioration in Indian earnings, it may not. Third, look at the sectors and stocks, not only the totals. Institutions do not buy and sell everything at the same time, so check which sectors they are adding and which they are reducing. Fourth, check the shareholding pattern each quarter, as we explained in our earlier article, to see how foreign and domestic holdings in your own stocks are changing. Fifth, remember that a heavy FII share in a stock makes its price more sensitive to global flows, while a stock with strong domestic institutional holding may be steadier in a global sell off, though neither is a guarantee.

This also bears on how you balance your portfolio between large, mid and small companies. Foreign selling tends to hit large, liquid companies first, while smaller companies depend more on domestic liquidity and sentiment and can fall further when that liquidity weakens. Spreading your money across all three groups, and across sectors, reduces the effect of any one source of flows.

Mistakes to avoid

The first mistake is to treat one day of FII or DII data as a signal. The second is to think that either group alone decides the market. The third is to assume that DII buying will always cushion falls. The fourth is to forget that flows follow prices as well as lead them. The fifth is to rely on provisional numbers from a single website. The sixth is to ignore the global causes of foreign selling and to blame Indian companies for it. The seventh is to forget that large, mid and small companies are affected differently. The eighth is to base a buy or sell decision on flows without checking the business and the valuation. This article is for education and is not a recommendation to buy or sell any stock, and every investment in the stock market carries risk, including the risk of loss of capital.

FIIs and DIIs both move the market, in different ways. Foreign investors react to global rates, the dollar, oil and valuations, and they set the tone for large companies and the rupee. Domestic institutions invest a steady flow of Indian savings, and they now own more of the market than foreigners do, which gives the market a cushion. The price on any day depends on who is the marginal buyer and seller, and flows are one of several forces together with earnings, interest rates and sentiment. For a long term investor, the sensible use of the data is to follow the trend and the reasons behind it, look at your own stocks and sectors, spread your money across large, mid and small companies, and let research on the business, not the daily flow number, decide what you do.

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