Anchor investors in an IPO and their lock-in period
Updated 26 October 2026 · 5 min read
Anchor investors are large institutional investors, such as mutual funds, insurance companies, pension funds and foreign portfolio investors, who are allotted shares in a mainboard IPO one working day before it opens to the public. Their shares come out of the QIB portion, and they cannot sell them straight away: half are locked in for 30 days from allotment and the rest for 90 days.
Anchors matter to ordinary investors in two ways. A strong anchor book is read as early institutional confidence in the issue, and the dates on which their lock-in ends are watched because a large block of shares becomes free to sell. This guide covers who anchors are, the rules that apply to them, why lock-in expiry dates can affect the share price and where to find the anchor list for any IPO.
Who anchor investors are
Anchors are qualified institutional buyers who commit large sums before the public bidding starts. The minimum anchor application is ₹10 crore, which keeps the category limited to big institutions. Typical anchor books include domestic mutual funds, insurers and foreign funds; the exact list differs for every issue.
The main rules
| Rule | What it says |
|---|---|
| Portion | Up to 60% of the QIB portion can be allotted to anchors |
| Timing | Anchors bid one working day before the issue opens |
| Minimum application | ₹10 crore |
| Lock-in, first half | 50% of anchor shares locked in for 30 days from allotment |
| Lock-in, second half | Remaining 50% locked in for 90 days from allotment |
| Subscription data | Anchor shares are excluded from the public subscription figures |
Further details, such as reservations for domestic mutual funds within the anchor portion and price adjustments, are set out in SEBI rules and each RHP.
Why companies use anchors
For a retail investor, the anchor book is one of the first pieces of hard information about an issue. It is published before you have to decide whether to apply, unlike subscription figures, which build up over the bidding days, and unlike GMP, which is unofficial. That makes it worth a look, as long as it is read for what it is: the choice of a small group of institutions at a fixed price.
Anchors give an issue a base of committed demand before the public sees it. The names in the anchor book and the amount they took are public by the time bidding opens, and many investors look at them as a sign of how professional investors view the company at that price. A well-known set of anchors can lift sentiment; a thin anchor book can cool it.
Keep in mind that anchors get shares without a lottery and at a fixed price, and that institutions have their own reasons for investing, including portfolio rules and index weightings. Their presence is a signal of interest, not a recommendation for you.
Why lock-in expiry dates matter for the share price
When a lock-in ends, shares that could not be sold become free to trade. For a large IPO this can be a substantial number of shares compared with the shares that normally trade each day. Some investors expect extra selling around these dates, especially if the share price has risen well above the anchor price and anchors are sitting on large gains.
- The 30-day date frees half of the anchor shares; the 90-day date frees the rest.
- Lock-in ending does not mean anchors will sell. Many hold for much longer, and some add more.
- Markets often anticipate these dates, so any price effect may come before, on or after the actual day, or not at all.
- Other lock-ins also end over time, such as those on promoter and certain pre-IPO shareholdings, and are listed in the RHP.
Say an IPO allots 50 lakh shares to anchors on a given day. About 25 lakh shares become free to sell roughly a month later and another 25 lakh about three months after allotment. If the share normally trades only a few lakh shares a day, investors may watch both dates closely. This is an illustration only.
How to find the anchor list and dates
- Exchange announcements: the company files the anchor allocation with NSE and BSE, usually on the day of the anchor bid, listing each anchor and the shares allotted.
- The RHP and later the prospectus: the capital structure and offer sections explain the anchor portion and lock-in terms.
- Company announcements after listing, which may mention lock-in expiry or share movements.
- The IPO page here, which shows the dates timeline and links to the exchange documents for the issue.
Anchor allotment happens one working day before opening, and the lock-in runs from the date of allotment, so you can work out the approximate 30-day and 90-day dates from the anchor allotment date. Check the exact dates in the offer documents, as calculations around holidays can differ.
Common misunderstandings
- Anchors are not guaranteed to make money; they bear the same price risk once the lock-in ends.
- A big anchor book does not guarantee a good listing or long-term returns.
- Lock-in expiry is not a sell signal or a buy signal by itself. It is just a date when supply may change.
Frequently asked questions
What is the lock-in period for anchor investors?
50% of the shares allotted to anchors are locked in for 30 days from allotment, and the remaining 50% for 90 days from allotment.
How much of an IPO can go to anchor investors?
Up to 60% of the QIB portion of a mainboard IPO can be allotted to anchor investors, subject to the rules in the RHP.
When do anchor investors bid?
One working day before the IPO opens for public bidding. The anchor allocation is published on the exchanges.
Does share price always fall when anchor lock-in ends?
No. Lock-in expiry only means anchors are free to sell. Many keep holding, and the market may have already priced in the date.
Where can I see which anchors invested in an IPO?
In the anchor allocation announcement the company files on NSE and BSE, and in the offer documents. IPO pages here link to the exchange documents.