Lock-Up Period (IPO)
The post-IPO waiting room - insiders can't sell for months, holding back a wave of selling until the stock finds its footing.
- Term
- Lock-up period
- Typical length
- 90–180 days post-IPO
- Restricts
- Insiders from selling shares
- Expiry
- Can pressure the stock as selling opens
Forms & parts of speech
Definition in plain terms
A lock-up period is a contractual agreement, set as part of an IPO, that prevents company insiders - founders, executives, employees, and early investors like venture-capital firms - from selling their shares for a defined time after the company goes public, commonly 90 to 180 days.
Its purpose is to protect the newly public stock: if everyone who held pre-IPO shares could sell immediately, the sudden flood of supply could crater the price and signal a lack of insider confidence.
By staggering when insiders can sell, the lock-up gives the stock time to establish a trading history and stable demand. When the lock-up expires, a wave of previously restricted shares can come to market, which sometimes pressures the price as that new supply arrives.
Why it matters to growth leaders
The lock-up period is where the abstract value of equity becomes concrete - and delayed - for a growth leader who holds it.
Even after the company goes public and the stock trades, insiders typically can't convert their shares to cash until the lock-up expires, so the IPO is a milestone but not an immediate payday for employees. Understanding this manages expectations for oneself and one's team.
More broadly, the lock-up expiry is a known event that can move the stock, as a large block of insider shares becomes sellable - relevant context for anyone tracking the company's post-IPO trajectory.
For a growth leader, the lock-up is a reminder that public-market liquidity for insiders is deliberately phased, and that the company's share-price stability in the early public months is something the structure is explicitly designed to protect.
a contractual restriction barring insiders like founders, employees, and early investors from selling their shares for a set time, commonly 90 to 180 days after listing.
The purpose is to protect the new stock: if everyone holding pre-IPO shares could sell at once, the flood of supply could crater the price and signal weak insider confidence, so the lock-up staggers when insiders can sell and lets the stock establish stable trading first.
The growth leader uses this to set honest expectations, for personal equity and for the team's: the IPO is a milestone, but liquidity is phased and delayed.
The leader also notes that the lock-up's expiry is a known event - when the restricted shares become sellable, the added supply can pressure the price.
Understanding the lock-up, the growth leader reads the company's early public months realistically, recognizing that the structure deliberately protects share-price stability while delaying when insiders can actually cash out.
and failing to set realistic liquidity expectations for an equity-holding team.
Synonyms & antonyms
Synonyms
Antonyms
Origin & history
The lock-up period became a standard IPO feature to prevent insider selling from overwhelming a newly listed stock; by phasing when founders, employees, and early investors can sell, it supports early price stability - and its expiry is a watched event in a stock's first months.
Etymology: source.
Usage trends
Search interest for this term over the last five years:
Common questions
- What is an IPO lock-up period?
- A contractual restriction, commonly 90 to 180 days after an IPO, during which company insiders are barred from selling their shares — preventing a flood of insider selling that could destabilize the new stock.
- Why do lock-up periods exist?
- To protect the newly public stock: without them, a flood of insider shares could crater the price and signal weak confidence, so the lock-up lets the stock establish stable trading before insiders can sell.
- What happens when a lock-up expires?
- A large block of previously restricted insider shares becomes sellable, which can add supply and sometimes pressure the stock price around the expiry date.
Related tools & calculators
Resources & people to follow
- referenceWikipedia — lock-up period
- referenceCapital-markets and growth-finance practice
- referenceRGM analysis — an IPO is a milestone, not an immediate payday; insider liquidity is phased, and lock-up expiry is a known event that can move the stock
Curated, non-competitor resources verified per term.
Related training
Disciplines
Areas of marketing where lock-up period (ipo) is a core concern: