• OpenAI announces it has filed its confidential S-1 to go public.
• The draft brings Sam Altman's company a step closer to a huge IPO and the public markets.
• OpenAI's post said the company has not yet decided on the timing of the IPO.

OpenAI has filed its confidential S-1, the first official step toward a blockbuster IPO.

The ChatGPT-maker announced the filing on Monday in a short, blunt blog post. The confidential S-1 draft gives the U.S. Securities and Exchange Commission time to review OpenAI's plans for an eventual public listing — though the post made it sound like that could be a ways out.

"We expect it to leak so we're just announcing it," OpenAI's post said. "We have not decided on timing yet; it may be a while because there are things we want to do that are likely easier as a private company."

It continued: "But it's a complicated set of tradeoffs and this gives us the option to go public sooner if that ends up being best."

OpenAI did not immediately respond to Business Insider's request for comment.

This is a developing story.