Glossary
Markets & macro

Lock-up period

The window after an IPO in which insiders are forbidden from selling.

Typically 90 to 180 days. When it expires, a large volume of shares can suddenly become sellable, and prices frequently come under pressure.

Watching the lock-up expiry calendar tells you when supply is about to arrive, regardless of what the business is doing.

Figure

Who the first-day pop actually enriched

Offer price, £20Opens at £28You buy here£8 per share the company never receivedThen the lock-up expires and insiders can sell.

If the shares open 40% above the offer price, that 40% is money the company could have raised and did not. It went to whoever was allocated shares at the offer, which was not you.

Why it matters

It is a scheduled, predictable supply shock, which is a rare thing in markets.

The mistake everyone makes

Being surprised by a price fall on a date that was known in advance.

Related terms

See Lock-up period on a real company

SteadyShares pulls this straight from the filings for 1,100+ companies, alongside moat scores, DCF fair value and peer comparison. Free to look around.

Open SteadyShares