Should the Massive Coming IPOs Affect Your Investment Strategy?

Some of the world’s most valuable private companies are moving toward the public markets. SpaceX has already completed a massive public offering, while OpenAI and Anthropic have both taken steps toward potential IPOs.[1]

 

These companies are large enough that their arrival could affect more than investors who buy their shares directly. They may eventually appear in major stock indexes, mutual funds, exchange-traded funds and retirement accounts.

 

That raises a reasonable question:

 

Should investors change their strategy before these companies enter the market?

The concern about limited supply

When a company first goes public, only a portion of its total shares is normally available for trading. Founders, employees and early investors are generally prohibited from selling their shares for a period of time following the IPO.

 

This temporary restriction is known as a lockup.

 

A limited initial supply can help support the stock price when investor demand is strong. SpaceX provides a recent example. Its shares initially climbed well above the offering price but later gave back much of that gain as investors began focusing on valuation, business results and the approaching release of insider shares.[2]

 

When a lockup expires, substantially more shares may become available for sale. Employees may want to diversify, early investors may want to realize gains, and investment funds may be required to return money to their own investors.

 

That additional supply can put downward pressure on the stock.

 

Historical research supports that concern, although the average effect has been relatively modest. One widely cited study found that trading volume increased approximately 40% following lockup expirations and that stocks experienced an average abnormal decline of about 1.5% over a three-day period.[3]

 

That is meaningful, but it is not the same as predicting a collapse.

 

Will there be enough buyers?

There will almost certainly be buyers. The more important question is:

 

At what price will buyers be willing to step in?

 

Large institutional investors may want exposure to OpenAI, Anthropic or SpaceX. Index funds may eventually be required to purchase them. Individual investors may also buy them through brokerage accounts, mutual funds or workplace retirement plans.

 

However, this demand does not guarantee that the stocks will maintain their IPO prices. If insider selling is heavy, the price may need to fall before buyers view the shares as attractive.

OpenAI and Anthropic have not yet publicly disclosed their final offering sizes, initial public floats or lockup schedules. OpenAI has said that it has not decided on the timing or terms of its offering, and recent reports suggest its IPO may be delayed until 2027. Anthropic has also taken steps toward an offering, but its final structure remains unknown.[4]

 

Any estimate of how many shares will initially trade—or how many will become available after the first lockup—should therefore be treated as speculation until each company publishes its formal securities filings.

 

Could these IPOs hurt the broader market?

The larger concern may not be the individual lockup periods. It may be the amount of investment capital needed to absorb several enormous companies entering the market within a relatively short period.

 

Money used to purchase newly public companies has to come from somewhere. Investors may contribute new cash, but institutions may also sell existing holdings to make room.

That could temporarily redirect money away from other large technology and growth stocks. It could also increase the concentration of major indexes if a small number of extremely valuable companies quickly become prominent holdings.

 

Still, these events are unlikely by themselves to justify abandoning a well-diversified investment strategy.

 

A broadly diversified investor may eventually own these companies indirectly through index funds. Their portfolio weight will generally rise or fall based on their market values rather than on an investor’s ability to predict the best IPO or lockup date.

 

What should investors do?

For most long-term investors, the answer is not to make a major portfolio change in anticipation of these IPOs.

Instead:

• Maintain an appropriate level of diversification.

• Avoid chasing a company simply because its IPO receives significant attention.

• Recognize that a limited initial supply can create unusually high prices.

• Be cautious about purchasing before a large lockup expiration.

• Review how much exposure you already have to technology and other growth-oriented companies.

Investors who receive shares through employment have a different decision. Employees of these companies may eventually have a large portion of their wealth tied to a single stock. For them, the end of a lockup period may provide an important opportunity to diversify—even if they remain confident in the company.

 

The takeaway

The arrival of companies such as SpaceX, OpenAI and Anthropic could create considerable excitement and short-term market volatility.

 

Lockup expirations may place pressure on individual stocks, and large IPOs could temporarily redirect money away from existing companies. But neither development changes the basic principles of long-term investing.

 

The best defense is not predicting exactly when insiders will sell or whether a stock will rise immediately after its IPO.

 

It is maintaining a portfolio that does not depend too heavily on the success—or the initial trading price—of any one company.

---

Sources

[1] Reuters, “OpenAI files for U.S. IPO after Anthropic as AI giants head to public markets,” June 8, 2026. OpenAI and Anthropic had confidentially filed, although timing and offering terms remained uncertain. ( Reuters)

[2] Reuters, “SpaceX shares slide below IPO price for the first time as blistering rally unravels,” July 15, 2026; Reuters, “SpaceX selloff an ominous sign as lockup expiry looms,” July 16, 2026. ( Reuters)

[3] Laura Casares Field and Gordon Hanka, “The Expiration of IPO Share Lockups,” Journal of Finance , 2001. The study reported a permanent 40% increase in average trading volume and an approximately 1.5% three-day abnormal return around expiration. ( JSTOR)

[4] Reuters, “OpenAI joins Anthropic in IPO push,” June 8, 2026; Reuters, “OpenAI leans toward waiting until next year for IPO,” June 25, 2026. ( Reuters)