IPO Lock-in Period Explained (2026) — Anchor, Promoter & Pre-IPO Holders

A complete guide to SEBI's mandatory lock-in periods for different categories of IPO shareholders — when each lock-in expires, why it matters for retail investors, and how to read post-lock-in supply patterns.

By IPO Cracker Editorial Team · 9 min read · Updated · Editorial Policy · Data Sources

An IPO lock-in period is a SEBI-mandated window during which certain categories of pre-listing shareholders are prohibited from selling their shares post-listing. The purpose is to prevent disorderly supply hitting the market right after listing — and to ensure that early-stage investors (anchor institutions, promoters, pre-IPO backers) have skin in the game during the critical early trading period. For retail investors, understanding when each lock-in expires is one of the most reliable ways to anticipate post-listing supply pressure.

Quick answer: Anchor investors are locked in for 30 days (50% of allocation) and 90 days (remaining 50%). Promoters' minimum 20% contribution is locked in for 18 months; excess promoter holding for 6 months. Non-promoter pre-IPO shareholders (VCs, PE, angel investors, founders excluding promoters) are locked in for 6 months.

Why Do Lock-in Periods Exist?

Lock-ins serve three regulatory purposes set by SEBI under the ICDR Regulations:

  • Price stability post-listing — without lock-in, anchor investors and pre-IPO holders could dump shares immediately after listing, creating a massive supply shock. Lock-ins force them to stay invested and absorb early volatility.
  • Skin in the game — promoters need to prove they aren't running a "pump and exit" on the public market. The 18-month lock-in on the minimum 20% post-issue capital ensures continued alignment with public shareholders.
  • Information signal — lock-ins are public information. The market knows precisely when each tranche unlocks, allowing rational price discovery rather than surprise dumps.

The 4 Lock-in Categories — Quick Comparison

Category Who Lock-in Period From When
Anchor — Tranche 1 Anchor investors (50% of their allocation) 30 days Date of allotment
Anchor — Tranche 2 Anchor investors (remaining 50% of their allocation) 90 days Date of allotment
Promoter — Minimum Contribution Promoters' minimum 20% of post-issue paid-up capital 18 months Date of allotment in the IPO
Promoter — Excess Holding Promoter shares above the 20% minimum 6 months Date of allotment in the IPO
Pre-IPO Non-Promoter VCs, PE, angel investors, employees with pre-IPO ESOPs, founders excluding promoters 6 months Date of allotment in the IPO

Anchor Investor Lock-in — 30 / 90 Day Split

Anchor investors (mutual funds, FPIs, insurance companies, pension funds) are allocated up to 60% of the QIB portion one working day before the public issue opens. Their lock-in is split into two tranches:

  • 50% of anchor allocation → locked for 30 days from allotment
  • Remaining 50% → locked for 90 days from allotment

This split was introduced by SEBI in 2022, building on the earlier 30-day blanket lock-in. The 90-day extension was added specifically to prevent early-exit selling that was destabilising newly listed stocks. Note: anchor investors invest at the upper price band, so they have no price discount — only allocation certainty + early access. Read our full Anchor Investor guide →

Promoter Lock-in — 18 Months and 6 Months

Promoter lock-in is structured in two layers under SEBI ICDR Regulations:

  • Minimum 20% of post-issue paid-up capital held by promoters → locked for 18 months from the date of allotment in the IPO. This is the "skin in the game" lock-in. The 18-month period replaced the earlier 3-year requirement under SEBI's 2021 reforms (for IPOs where the issue object is only OFS or non-capex; the 3-year lock-in was retained for issues funding capital expenditure for a specific project — though SEBI has since further harmonised this).
  • Promoter shares above the 20% minimum → locked for 6 months from allotment. This is to prevent immediate post-listing exits while still allowing some flexibility.

Pre-IPO Non-Promoter Lock-in — 6 Months

The entire pre-issue share capital held by non-promoter shareholders is locked in for 6 months from the date of allotment. This category is the broadest and includes:

  • Venture Capital (VC) and Private Equity (PE) investors who funded the company before IPO
  • Alternative Investment Funds (AIFs) with pre-IPO holdings
  • Angel investors from earlier funding rounds
  • Employees holding ESOPs exercised before the IPO (specific company ESOP terms may add additional vesting)
  • Family members, founders, and other early backers who are not classified as promoters under the prospectus

The 6-month period replaced the earlier 1-year lock-in under SEBI's 2021 reforms aimed at making Indian IPOs more competitive vs alternative listing venues.

2026 Update — Pledged Shares Automation

In March 2026 SEBI amended the ICDR Regulations, and an April 2026 circular put the change into operation. Depository systems cannot create a lock-in on shares that are pledged, which made pledged pre-IPO shares held by non-promoters hard to lock in. Now, on the issuer's instruction, the depositories can record such shares as "non-transferable" for the applicable lock-in period instead.

For retail investors, this is a process improvement that should reduce IPO listing delays — but doesn't change the lock-in window itself.

What Happens on Lock-in Expiry?

On the day a lock-in tranche ends, the previously-locked shares become freely transferable. Owners are not required to sell — but they now can. Three patterns commonly emerge:

  • 30-day anchor unlock — first half of anchor allocation becomes free. Some short-term tactical anchors (hedge funds, arbitrage AIFs) may book profits; long-only mutual funds typically hold longer. Expect mild selling pressure on the unlock day and the immediately following sessions.
  • 90-day anchor + 6-month pre-IPO unlock — these are the bigger events. The combined supply from VCs, PE investors, and the second anchor tranche can create meaningful selling pressure. Stocks often trade weak for 1-2 weeks around the 6-month mark, especially if pre-IPO investors were sitting on large gains.
  • 18-month promoter unlock — typically not a sell event because promoters have long-term skin in the game. But it does increase the float marginally and removes a regulatory constraint.

How Retail Investors Should Read Lock-in Expiry

Lock-in expiry is one of the most reliable signals retail investors can plan around:

  1. Note the lock-in expiry dates when you buy a recently listed IPO. Most brokerage platforms list these alongside the IPO data.
  2. Check the magnitude — a stock with 60% of float still locked at the 6-month mark faces much bigger supply unlock than one where promoters held only 30%.
  3. Watch the price action 2-3 weeks before unlock — savvy holders sometimes pre-empt the unlock by selling early or hedging via derivatives. Volume increases ahead of unlock are a warning sign.
  4. Don't panic-sell on unlock day — many high-quality companies absorb the unlock smoothly because long-term holders simply don't sell. Lock-in expiry is a supply event, not a fundamental event.
  5. Look for fundamental support — if the company is delivering on its growth plan, lock-in unlock supply is typically absorbed within 1-2 quarters.

Lock-in Expiry — Real Market Impact

For individual stocks, the question isn't whether a price dip happens around unlock — it's whether the underlying business is delivering enough to justify holders staying invested through it.

Lock-in for SME IPOs vs Mainboard

The same SEBI ICDR lock-in framework generally applies to both Mainboard and SME IPOs. Specifics:

  • Anchor lock-in — 30/90-day split applies to both Mainboard and SME (where SME issues have anchor allocation, which is increasingly common for larger SME IPOs).
  • Promoter lock-in — 18-month minimum contribution + 6-month excess applies to both.
  • Pre-IPO non-promoter lock-in — 6 months applies to both.

The main practical difference: SME IPOs have lower trading volumes, so even small post-unlock selling can move the price meaningfully. Mainboard liquidity absorbs supply more smoothly.

Common Misconceptions

  1. "All shares are locked-in for the full lock-in period." Wrong. Different categories have different windows. Retail investors who applied in the IPO have no lock-in at all — they can sell on listing day.
  2. "Lock-in expiry always crashes the price." Wrong. High-quality companies with strong fundamentals often absorb unlock supply with minimal impact. Crashes happen mostly when the business is underperforming.
  3. "Promoters cannot sell at all during the 18-month lock-in." Partially wrong. Promoters cannot sell their minimum 20% contribution during 18 months. Excess promoter holding has only a 6-month lock-in.
  4. "Lock-in is the same for all anchor investors." Wrong. Each anchor's allocation is split 50/50 — half unlocks at 30 days, half at 90 days.

How IPO Cracker Tracks Lock-in Data

For every IPO Cracker tracks, the IPO Detail page surfaces lock-in expiry dates derived from the allotment date:

  • Anchor 30-day expiry — date when first half of anchor allocation unlocks
  • Anchor 90-day expiry — date when second half unlocks
  • Pre-IPO and Promoter excess (6-month) expiry — date when bulk of pre-IPO supply unlocks
  • Promoter minimum (18-month) expiry — long-tail unlock

Use these dates as supply-event markers when planning entry / exit on listed IPO stocks.

Key Takeaways

  1. SEBI mandates lock-in to prevent disorderly post-listing supply and ensure pre-IPO investors stay aligned with public shareholders.
  2. Anchor investors: 50% locked 30 days, 50% locked 90 days from allotment. Promoters: minimum 20% locked 18 months, excess locked 6 months. Pre-IPO non-promoters: 6 months.
  3. Retail investors who applied in the IPO have no lock-in — they can sell on listing day.
  4. The biggest unlock event is usually the 6-month combined (90-day anchor tranche 2 + 6-month pre-IPO non-promoter + 6-month excess promoter).
  5. Lock-in expiry is a supply event, not a fundamental event — high-quality businesses absorb it; weak ones get punished.

Last updated: October 2026. SEBI ICDR Regulations governing lock-in are amended periodically; verify the current rules with the SEBI website (sebi.gov.in) before relying on specific durations for high-stakes decisions.

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Frequently Asked Questions

An IPO lock-in period is the SEBI-mandated window during which certain pre-listing shareholders are prohibited from selling their shares post-listing. Different categories have different lock-ins: anchor investors (30/90-day split), promoter minimum 20% contribution (18 months), promoter excess holding (6 months), and pre-IPO non-promoter shareholders like VCs, PE, angel investors, and ESOP holders (6 months).

Anchor investor lock-in is split into two tranches: 50% of allotted shares are locked for 30 days from the date of allotment, and the remaining 50% are locked for 90 days. The 90-day extension on half the allocation was introduced by SEBI in 2022 to prevent early-exit selling that was destabilising newly listed stocks.

Promoter lock-in is structured in two layers per SEBI ICDR: (1) the minimum 20% post-issue paid-up capital held by promoters is locked for 18 months from the date of allotment, and (2) any promoter shares held above this 20% minimum are locked for 6 months. The 18-month period replaced the earlier 3-year requirement under SEBI's 2021 reforms.

The entire pre-issue share capital held by non-promoter shareholders is locked in for 6 months from the date of allotment in the IPO. This includes Venture Capital and Private Equity investors, Alternative Investment Funds (AIFs), angel investors, employees holding pre-IPO ESOPs, and other non-promoter early backers. The 6-month period was introduced by SEBI in 2021, replacing the earlier 1-year lock-in.

No. Retail investors who apply for shares in an IPO have no lock-in period. Once shares are allotted and credited to your demat account, you are free to sell on listing day or hold for the long term — your choice. Lock-in applies only to anchor investors, promoters, and pre-IPO non-promoter shareholders.

On the day a lock-in tranche ends, previously-locked shares become freely transferable. Owners are not required to sell, but they can. Common patterns: short-term tactical anchors (hedge funds, arbitrage AIFs) often book profits at the 30-day anchor unlock, creating mild selling pressure. The 6-month combined unlock (90-day anchor tranche 2 + 6-month pre-IPO + 6-month excess promoter) is the biggest supply event. The 18-month promoter unlock is usually less impactful since long-term promoters tend to hold.

No. While lock-in expiry creates supply pressure, high-quality companies with strong fundamentals often absorb the unlock with minimal impact. Stocks tend to trade weak for 1-2 weeks around the 6-month mark, but this is typically a short-term supply event rather than a fundamental concern. Crashes happen mostly when the underlying business is underperforming. Lock-in expiry is a supply event, not a fundamental event.

Promoters cannot sell their minimum 20% post-issue contribution during the 18-month lock-in period. However, any promoter holding above this 20% minimum has only a 6-month lock-in and becomes transferable after that. So depending on the promoters' actual post-issue holding percentage, partial selling may be possible after 6 months while the core 20% remains locked for 18 months.

The SEBI ICDR lock-in framework — anchor 30/90 days, promoter 18 months minimum + 6 months excess, pre-IPO non-promoter 6 months — generally applies to both Mainboard and SME IPOs. The main practical difference is that SME IPOs have much lower trading volumes, so even small post-unlock selling can move the price meaningfully. Mainboard liquidity tends to absorb supply more smoothly.

In March 2026 SEBI amended the ICDR Regulations (put into operation by an April 2026 circular) so that pledged pre-IPO shares held by non-promoters, on which a normal lock-in cannot be created, can be recorded by the depositories as 'non-transferable' for the applicable lock-in period, ensuring compliance without requiring manual pledge release coordination that previously delayed some IPO listings. This is a process improvement and does not change the lock-in window itself.
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