What Is a Lock-Up Period? (IPO Lock-Up Explained)

A lock-up period is a set window of time after a company’s IPO during which insiders — founders, employees, and early investors — are not allowed to sell their shares. Lock-ups typically last 90 to 180 days.

Why do lock-up periods exist?

  • To prevent a flood of selling. If insiders dumped all their shares on day one, the price could crash.
  • To build confidence. It signals that insiders are committed for at least the lock-up window.
  • To protect new investors. It gives the market time to find a fair price.

Why lock-up expiry matters for the share price

When a lock-up period ends, a large number of new shares can suddenly hit the market. If many insiders decide to sell, the increased supply can push the share price down — at least temporarily. Experienced investors watch lock-up expiry dates closely.

This is one of the recurring reasons a stock “moves” — and exactly the kind of event we explain in our Why SPCX Moved Today posts.

What this could mean for SPCX

If SpaceX lists as SPCX, expect a lock-up period for insiders. The lock-up expiry date would become an important date to watch, because it could create downward pressure on the share price if insiders sell.

Specific SPCX lock-up terms will only be known once the official IPO prospectus is filed. Follow our IPO Tracker.


Educational content only. Not financial advice.

← All guides