IPO Lock-Up Expiry: What Happens on Day 181

When a company goes public, most insiders cannot sell their shares right away. Founders, employees and pre-IPO investors typically agree to a lock-up period, usually about 180 days, during which they are restricted from selling. When the lock-up ends, a large number of shares can become eligible for sale at once.

That moment, often called "day 181", can move a stock price and shape liquidity for everyone who owned shares before the IPO. This guide explains how lock-ups work, what tends to happen when they expire and how insiders and investors can plan.

1. What a Lock-Up Is

• A contractual agreement between insiders and the IPO underwriters, not a legal requirement in itself.
• Typically about 180 days after the IPO, though terms vary.
• Covers founders, executives, employees and pre-IPO investors, and often most pre-IPO shareholders.
• Purpose: to support an orderly market after listing by preventing a flood of insider selling.

2. Why Lock-Ups Have Become More Flexible

In recent years, many IPOs have included more flexible structures, such as:

• Staggered releases, where portions of shares unlock at different times.
• Early releases tied to share price performance, for example if the stock trades above a set level for a period after an earnings announcement.
• Earnings-linked releases, allowing sales after the company reports quarterly results.

3. What Happens When Lock-Ups Expire

• More shares become available, increasing potential supply.
• Share prices often weaken around expiry. Academic research has found that, on average, share prices tend to decline around lock-up expiration, though effects vary widely.
• Some insiders sell to diversify or pay taxes, while others hold.
• Venture funds may distribute shares to their LPs rather than selling themselves. See DPI vs. TVPI.

High-profile examples include Uber, whose shares fell to new lows around its first major lock-up expiry in November 2019.

4. Other Limits on Selling After Lock-Up

• Insider trading rules. Insiders cannot trade on material non-public information.
• Trading windows and blackout periods set by company policy, often closed around earnings.
• Rule 144 governs resales by affiliates and holders of restricted securities, including volume limits and filing requirements for affiliates.
• 10b5-1 plans let insiders set up pre-arranged trading plans. Rules updated in 2022 introduced cooling-off periods before trades can begin.
• Tax considerations, such as holding periods and option exercises. See ISOs vs. NSOs.

5. Planning for Founders and Employees

1. Understand your lock-up terms, including any staggered or early release provisions.
2. Plan diversification with a financial adviser before the lock-up ends.
3. Consider a 10b5-1 plan for orderly selling over time.
4. Plan for taxes on sales and option exercises.
5. Remember trading windows and insider trading rules.

6. What Public Investors Should Watch

• Lock-up expiry dates, disclosed in the IPO prospectus.
• The share of total shares becoming eligible for sale.
• Who holds those shares, such as venture funds likely to distribute.
• Early release conditions that could bring expiry forward.

Frequently Asked Questions

How long is a typical IPO lock-up?

Usually about 180 days, though terms vary and many recent IPOs include staggered or early release provisions.

Do stock prices always fall at lock-up expiry?

No, but research has found that prices tend to decline on average around expiry, reflecting expected selling.

Can underwriters release shares early?

Yes. Underwriters can agree to waive or modify lock-ups, and many agreements include automatic early release conditions.

What is a 10b5-1 plan?

A pre-arranged trading plan that lets insiders sell shares on a set schedule, helping them avoid insider trading concerns.

The Bottom Line

The lock-up expiry is often the first real liquidity moment for founders, employees and early investors. Understanding the terms, planning sales and taxes in advance, and watching for market effects helps insiders turn paper gains into real value and helps public investors anticipate volatility. See also secondaries and tender offers for pre-IPO liquidity.

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This article is general information, not investment, tax or legal advice.