Anthropic filed to go public—what retail investors should weigh before its IPO

Artificial intelligence company Anthropic filed an S-1 prospectus with the Securities and Exchange Commission on Monday. This filing shows that the company plans to go public soon. Anthropic, which is five years old and makes the AI assistant Claude, is expected to have one of the biggest initial public offerings (IPOs) in history. It could become the biggest if it raises more than the $75 billion SpaceX raised in its June debut.

Everyday investors may be excited about buying a piece of a company that looks like one of the big winners of the AI era. But, as with any investment, they should do their research instead of buying just because everyone is talking about it.

No one can predict the future, so there is no way to know for sure what a company's share price will do after its IPO. In its filing, Anthropic listed many risks. These include changes in government rules and politics, the possibility that AI could threaten humanity's future, and the huge amounts of electricity needed to power Anthropic's computers.

A company's share price on its first day of trading also does not always show how successful it will be in the long run. For example, Robinhood had a disappointing IPO on July 29, 2021, when its shares first traded at $38 each. The stock closed that day well below its opening price and fell below $7 a share in June 2022. But it later rose to a high of $143 in July 2025 and closed at about $95 on Tuesday. Uber had a similar experience when it went public in 2019. Its shares fell more than 7% after trading began, but they now trade about 46% above their original price.

There is some good news for people thinking about investing in Anthropic. Companies that already have strong sales records have often performed reasonably well after going public. From 1980 through 2024, companies that had at least $1 billion in sales during the previous 12 months earned average returns over the three years after their IPOs that were almost as high as those of the overall stock market. This comes from research by Jay Ritter, who leads the IPO Initiative at the University of Florida.

"Bigger companies, as measured by sales, whether it's $100 million or a billion, on average have pretty much matched the market," he says. "In other words, once it starts trading, the institutional investors setting the price on average have gotten it right."

Anthropic earned nearly $16.3 billion in revenue during the first half of 2026, according to its S-1 filing.

Still, its recent success does not mean investors should put all their money into this new stock.

Shares of popular companies often rise after their IPOs. From 1980 through 2025, stocks rose by an average of 19% above their offering price on their first day of trading, according to Ritter's research. The offering price is the price set by the banks managing the IPO before trading begins.

But everyday investors may not get this benefit because most shares sold at the offering price are usually set aside for large professional investors. Anthropic is considering making 15% to 20% of its IPO shares available to everyday investors through JPMorgan Chase & Co., Bloomberg reports. People who cannot buy shares through this offer will have to wait until the stock becomes available on the public market.

Even if Anthropic's share price jumps after its IPO and stays high for a while, Ritter says investors may have less room to make money because the company's value is already so high. "The upside is limited," he says.

Reports say Anthropic is aiming to go public with a company value of between $1.5 trillion and more than $2 trillion. Chipmaker Nvidia is currently the world's most valuable publicly traded company, worth $5.2 trillion. A company's market value is calculated by multiplying its share price by the total number of shares available. Anthropic could theoretically become worth even more than Nvidia, but Ritter says that would still leave less room for investors to make big gains than they might expect.

"When you're going public at a $1.5 trillion valuation, the possibility of making more than 10x is really limited," he says.

There are signs that Anthropic could keep its business strong. For example, its revenue is growing much faster than its costs, Ritter says. Still, he warns investors not to "put all your eggs in one basket" when investing in any public company. He recommends using only "play money" that you can afford to lose when buying individual stocks, rather than putting a large part of your main investment savings into one company. Overall, he advises investors to keep their investment plans simple and steady.

His best advice for most investors is to buy and hold low-cost index funds. If you do this, you may not even need to buy Anthropic shares yourself to have some investment in the company. Because Anthropic could become such a large company after its IPO, its stock may soon be included in funds such as the Vanguard Morningstar Total Stock Market Fund. These funds aim to follow the performance of the overall U.S. stock market, Ritter says.