What Is the Lock-In Period for IPO Anchor Investors

What is the lock-in period for IPO anchor investors? It’s a two-step rule: half of the shares allotted to each anchor investor are locked for 30 days, and the other half for 90 days, both counted from the date of allotment. Until each date passes, the shares can’t be sold.

The Rule in Plain Terms

SEBI splits the lock-in so anchors can’t all leave at once.

• First 50%: locked for 30 days from the allotment date
• Remaining 50%: locked for 90 days from the allotment date
• Anchors can’t sell all their shares after 30 days, only half
• The rule was revised in 2022, replacing the earlier single 30-day lock-in with this staggered version

A Worked Example With Dates

Dates make the rule concrete, so here’s one published example.

• Allotment date: 15 January 2026
• First half unlocks on 14 February 2026
• Second half unlocks on 15 April 2026
• Other pre-IPO holders in the same example unlock later, on 15 July 2026, six months after allotment
• In other words, half of the anchor shares are still locked when the first batch becomes tradable

The Clock Starts at Allotment, Not Listing

This small detail trips people up when they mark calendars.

• Allotment happens on T+1, while listing is on T+3
• That makes the first unlock arrive roughly four weeks after the stock starts trading, not a full 30 days
• Some guides loosely say “30 days after listing,” so sources aren’t fully consistent here
• Use the allotment date as the starting point, since that’s what the rule specifies

Who Counts as an Anchor Investor

Only large institutions qualify, and they come in before the public does.

• Anchors are qualified institutional buyers (QIBs), such as mutual funds, insurers, pension funds and foreign portfolio investors
• Minimum commitment is ₹10 crore in a mainboard IPO and ₹2 crore in an SME IPO
• The anchor round takes place one working day before the issue opens, with full payment up front
• Allocation details are disclosed to the exchanges before public bidding begins
• Up to 60% of the QIB portion can go to anchors, which works out to at most about 30% of the whole issue in a standard structure

The Reserved Slice for Domestic Funds

The anchor book also has a carve-out meant to bring in local institutions.

• Older guides say one-third of the anchor portion is reserved for domestic mutual funds
• Two newer guides describe a late-2025 amendment lifting the reserved share to 40%, split into 33% for mutual funds and 7% for insurers and pension funds
• Check the offer document for the issue you’re looking at, since the figure you see in older articles may be out of date

Why SEBI Imposes the Lock-In

The rule exists to stop early profit-booking from shaking a new listing.

• It prevents anchors from selling the moment a listing pops
• It gives the stock a steadier base of institutional holders in its first weeks
• The 90-day second tranche stops a single large wave of selling at one date
• Anchor participation also acts as a vote of confidence before retail bidding opens

What Happens When the Lock-In Ends

Expiry dates matter because they can add supply to the market.

• When shares unlock, anchors can sell, which can add selling pressure
• Analysts watch anchor trading after expiry as a clue to institutional sentiment
• Share India’s commentary on post-IPO weakness notes that after lock-in periods expire, many holders book profits, creating sudden supply pressure
• Expiry is no guarantee of a fall, since an anchor may simply hold on
• A stock that has risen sharply by the unlock date is more exposed to profit-taking than one that hasn’t

How to Find the Dates for a Specific IPO

You don’t need to calculate from scratch if you know where to look.

• The anchor list and allocation size appear on the exchanges and in broker IPO pages a day before opening
• The allotment date comes from the issue timetable or the registrar
• Add 30 and 90 days to that date to mark the two unlocks
• Some IPO trackers publish lock-in expiry calendars for recent listings

FAQs

Q1. Can anchor investors sell all their shares after 30 days?

No. Only 50% of their allotted shares unlock after 30 days. The other 50% stays locked for 90 days from the allotment date.

Q2. Is the lock-in counted from listing or allotment?

From the date of allotment, per the rule. Some guides loosely say “after listing,” but allotment comes first, so unlock dates arrive slightly earlier than a listing-based count suggests.

Q3. What is the minimum an anchor investor must invest?

₹10 crore in a mainboard IPO and ₹2 crore in an SME IPO. Anchors must be QIBs and invest one working day before the issue opens.

Q4. Do other shareholders have lock-ins too?

Yes. Promoters and pre-IPO investors face their own separate lock-ins, which differ from the anchor rule. In one 2026 example, pre-IPO and excess promoter holdings unlocked six months after allotment.