Lock-in periods restrict certain shareholders from selling their shares for a fixed duration after the IPO. SEBI rules require promoters to lock in at least 20% of post-issue capital for 18 months (reduced from three years in 2021) and the balance for six months. This is intended to demonstrate skin-in-the-game.
Anchor investors have a split lock-in: 50% of allotted shares for 30 days from allotment date, the remaining 50% for 90 days. Pre-IPO investors (PE / VC funds, employee stock options, founder family) typically have a 6-month lock-in, though specific arrangements can vary.
Lock-in expiry dates are widely watched. Large blocks unlocking can briefly weigh on the stock price — the 90-day anchor unlock and the 6-month pre-IPO unlock are the two most-tracked events post-listing. Investors can find the lock-in schedule in the RHP and on the exchange's filing portal.