Unlocking IPO Lock-Up Periods: What You Need to Know


An IPO lock-up period, lasting typically between 90 to 180 days, plays a pivotal role in the stock market. This phase prevents major stakeholders from selling their shares immediately after an IPO, ensuring market stability. This comprehensive guide explores the intricacies of IPO lock-ups, their significance, and their impact on stock prices. It also addresses frequently asked questions and examines the pros and cons of this crucial phase in a company’s journey to going public.

Understanding IPO lock-ups

An initial public offering (IPO) lock-up period is a critical component of the IPO process. It serves the essential purpose of preventing a sudden influx of a company’s shares into the market. During this period, which typically spans 90 to 180 days, certain stakeholders are restricted from selling their shares. These stakeholders usually encompass insiders, such as the company’s founders, owners, managers, and employees, and may also extend to early investors, including venture capitalists.

The rationale behind implementing an IPO lock-up period is to maintain market stability and prevent a scenario where a large shareholder attempts to offload all their holdings immediately after the IPO. Such a massive sell-off could have a detrimental impact on the stock’s price, affecting all shareholders negatively. Empirical data suggests that after the conclusion of the lock-up period, stock prices often experience a permanent drop of approximately 1% to 3%.

Pros and cons of IPO lock-up periods


Here is a list of the benefits and drawbacks associated with IPO lock-up periods.

  • Promotes market stability by preventing a sudden influx of shares.
  • Allows for the establishment of share prices based on natural supply and demand.
  • Provides an opportunity for additional earnings reports, enhancing investor understanding.
  • May limit liquidity in the early post-IPO period.
  • Can lead to short-term price volatility as the expiration date approaches.
  • Investors should be aware of potential price drops after lock-up periods conclude.

The role of SEC filings

Information about a company’s lock-up period(s) can typically be found in its S-1 filing with the United States Securities and Exchange Commission (SEC). Any modifications to these lock-up periods are typically announced through subsequent S-1A filings. Importantly, it’s worth noting that lock-up periods are not mandated by the SEC or any other regulatory body. Instead, they are either voluntarily imposed by the company itself or required by the investment bank underwriting the IPO. Regardless of the source, the primary objective remains the same: to maintain robust stock prices following the company’s public debut.

The usefulness of lock-up periods

Lock-up periods play a pivotal role in allowing newly issued shares to find stability in the market without being subjected to immediate selling pressure from insiders. This cooling-off phase enables the market to determine share prices based on natural supply and demand dynamics. While liquidity may be relatively low initially, it tends to increase over time as trading ranges become established.

Furthermore, option contracts may commence trading during the lock-up period, contributing to stability and liquidity. The lock-up period also provides an opportunity for up to two consecutive earnings reports to be released, offering investors greater insight into the company’s operations and outlook.

Lock-up expiration

As the lock-up expiration date approaches, traders often anticipate a potential price drop due to the increased supply of shares entering the market. This anticipation can lead to a surge in short interest as traders engage in short-selling activities ahead of the expiration. Investors concerned about the impending lock-up expiration may employ strategies such as collaring or hedging to protect their long positions through options.

It’s worth noting that while stocks tend to experience sell-offs before a lock-up expiration, this doesn’t always result in sustained selling pressure. In some cases, if the pre-expiration sell-off is overly dramatic, it can trigger a short squeeze on the expiration day as short-sellers rush to cover their positions, potentially driving the stock price higher.

A notable example of this occurred with Shake Shack Inc., which experienced a short squeeze following its first lock-up expiration in July 2015, causing its stock price to surge by over 30% in less than two weeks. Margin interest had soared to over 100% as traders sought to borrow shares for short-selling.

Frequently asked questions

Can IPO lock-up periods be extended?

No, IPO lock-up periods are typically set and disclosed by the company or the underwriting investment bank. Once established, they are not typically subject to extension unless specified in the initial agreement. It’s crucial for investors to refer to the company’s SEC filings for accurate lock-up period details.

Are lock-up periods common for all IPOs?

Lock-up periods are a common feature of many IPOs, but they are not universal. Their presence or absence can depend on various factors, including the company’s specific circumstances and the preferences of its stakeholders. Investors should research each IPO individually to understand its lock-up period status.

Can lock-up periods impact stock volatility?

Yes, lock-up periods can influence stock volatility. As the expiration date approaches, market participants may anticipate price fluctuations, leading to increased trading activity. This heightened volatility can impact stock prices, potentially creating opportunities for both short-term traders and long-term investors.

Key takeaways

  • An IPO lock-up period, lasting 90 to 180 days, restricts certain stakeholders from selling their shares after an IPO, promoting market stability.
  • Lock-up periods are not mandated by regulatory bodies but are typically self-imposed by the company or required by the IPO’s underwriting bank.
  • These periods allow for the market to establish share prices naturally, with liquidity increasing over time.
View Article Sources
  1. The Design of IPO Lockups – University of Colorado
  2. Understanding Lockups: Effects in Bankruptcy and the Market for Corporate Control – University of Pennsylvania Carey Law School
  3. Tender Offers, Lock-ups and the Williams Act: A Critical Analysis of Mobil Corp. v. Marathon Oil Co. – Duquesne Law Review
  4. Pre IPO Investing: Here’s How It Works – SuperMoney
  5. Going Public: A Beginner’s Guide to Initial Public Offerings (IPOs) – SuperMoney