SAN FRANCISCO, United States (AFP)—ChatGPT-maker OpenAI on Monday took the first step toward going public, one week after arch-rival Anthropic announced its own filing, as both companies look to raise the massive sums needed to expand.

In a social media post, the Sam Altman-led company said it had confidentially submitted an S-1 registration statement to US securities regulators but had “not decided on timing yet” for any potential debut.

OpenAI’s move follows a confidential filing by Anthropic, the maker of the Claude chatbot, which announced last Monday that it had taken the same step.

“It may be a while because there are things we want to do that are likely easier as a private company,” OpenAI said, while noting the filing gives it “the option to go public sooner if that ends up being best.”

Going public — known as an IPO, or initial public offering — means ordinary investors can buy a slice of a company for the first time. It is also one of the biggest ways a company can raise money fast.

Founded in San Francisco in 2015 as a nonprofit research lab by Altman, Elon Musk and others, OpenAI burst into the mainstream with the launch of ChatGPT in November 2022.

The company has since restructured as a for-profit corporation and has grown into one of the world’s most valuable private companies.

Training and running cutting-edge AI models require billions of dollars in computing infrastructure, and both OpenAI and Anthropic have been spending heavily to secure data center capacity and chips amid fierce competition to lead the industry.

Both companies have also raised record amounts of private investment to meet their ambitions, a process that may have reached its limits, forcing a turn to Wall Street for still more funding.

But going public requires making a company’s internal finances public, a process that both loss-making companies will want to delay for as long as possible.

OpenAI acknowledged the decision involved “a complicated set of tradeoffs” but said the filing preserves its flexibility.

Anthropic, valued at $965 billion following a $65 billion fundraising round, has positioned itself as a safety-focused rival to OpenAI in the generative AI race.

OpenAI was valued at $852 billion in March, putting it behind Anthropic by that measure heading into what analysts say could be a landmark period for AI listings.

Both companies appear set to follow Musk’s SpaceX to Wall Street.

SpaceX, which absorbed Musk’s xAI lab, could see shares begin trading as early as Friday, targeting a valuation of roughly $1.75 trillion in what would be the largest IPO in history.

OpenAI said it decided to get ahead of the news, predicting the document would surface regardless. “We expect it to leak so we’re just announcing it,” the company said.