OpenAI is preparing to sell around $6 billion in stock as part of a secondary sale that would value the company at roughly $500 billion, CNBC confirmed Friday.

The shares would be sold by current and former employees to investors including SoftBank, Dragoneer Investment Group and Thrive Capital, according to a person familiar with the negotiations who asked not to be named due to the confidential nature of the discussions. The talks are still in early stages and the details could change.

Bloomberg was first to report the discussions. All three firms are existing investors in OpenAI, but Thrive Capital could lead the round, as CNBC previously reported. SoftBank, Dragoneer and Thrive Capital did not immediately respond to CNBC’s request for comment.

OpenAI’s valuation has grown exponentially since the artificial intelligence startup launched its generative AI chatbot ChatGPT in late 2022.

The company announced a $40 billion funding round in March at a $300 billion, by far the largest amount ever raised by a private tech company. Earlier this month, OpenAI announced its most recent $8.3 billion in fresh capital tied to that funding round.

Last week, OpenAI announced GPT-5, its latest and most advanced large-scale AI model. OpenAI said the model is smarter, faster and “a lot more useful,” particularly across domains like writing, coding and health care. But it’s been a rocky roll out, as some users complained about losing access to OpenAI’s prior models.

“We for sure underestimated how much some of the things that people like in GPT-4o matter to them, even if GPT-5 performs better in most ways,” OpenAI CEO Sam Altman wrote in a post on X.

WATCH: OpenAI staffer reportedly to sell $6 billion in stock to SoftBank and other investors

The Bullish IPO this week took on added significance, perhaps because of the company name.

When shares of the Peter Thiel-backed cryptocurrency exchange more than doubled out of the gate on Wednesday before finishing the day up 84%, it was the latest sign that the tech IPO bulls are back in business.

In July, design software vendor Figma more than tripled in its New York Stock Exchange debut, and a month earlier shares of crypto firm Circle soared 168% in their first day on the Big Board.

Wall Street has been waiting a long time for this.

Three years ago, steep inflation and soaring interest effectively closed the market for public offerings. Tech stocks tanked and private capital dried up, forcing cash-burning startups to turn their attention away from growth and toward efficiency and profitability.

The roadblock appeared to be loosening earlier this year, when companies like StubHub and Klarna filed their prospectuses, but then President Donald Trump roiled the markets in April with his plans for sweeping tariffs. Roadshows were put on indefinite hold.

The president’s tariff agenda has since stabilized a bit, and investor money is pouring into tech, pushing the Nasdaq to record levels, up more than 40% from this year’s low in April. Optimism is growing that the hefty backlog of high-valued startups will continue to clear as CEOs and venture capitalists gain confidence that the public markets will welcome their top-tier companies.

Ahead of Figma’s debut, NYSE president Lynn Martin told CNBC’s “Squawk on the Street” that immense demand for that offering could “open the floodgates” for the rest of the market. And earlier this week, Nasdaq CEO Adena Friedman told “Fast Money” that there’s a “very healthy list” of companies looking to IPO in the second half of this year, ahead of the holiday season.

“I’ve been meeting a lot of CEOs, getting them prepared to think about what they want in the public markets and where they’re going,” Friedman said.

There are more than two-dozen venture-backed U.S. tech companies valued at $10 billion or more, according to CB Insights. StubHub has updated its prospectus, suggesting an offering is coming soon.

“The IPO window is open,” said Rick Heitzmann, a partner at venture firm FirstMark, in an interview with CNBC’s “Closing Bell” this week. “You’ve seen across industry, broad-based support for IPOs, and therefore, we’re advising companies we’re investing in to get ready and go public.”

Another big topic among VCs and bankers is the regulatory environment.

The Biden administration took heat from startup investors for cracking down on big acquisitions, mostly attributable to Lina Khan’s perceived heavy hand at the Federal Trade Commission, while also failing to ease restrictions that they say make it less appealing for companies to go public than to stay private.

Paul Atkins, the new head of the SEC, said in July he wants to “make IPOs great again,” by removing some of the impediments around the complexity of disclosures and litigation risk. He hasn’t offered many specific recommendations.

Friedman told CNBC that the first conversation she had with Atkins after he took the job was about making it easier and more attractive for companies to go public.

“The conversation was constructive along many fronts, looking at disclosure requirements, the proxy process, other things that really make it harder for companies to be public and navigate the public markets,” Friedman said. “He’s as interested as we are, so hopefully we’ll turn that into great action.”

In addition to the big gains notched by Bullish, Figma and Circle, the public markets welcomed online banking provider Chime with a 37% gain last month and trading app eToro with a 29% pop in May. The health-tech market has seen two IPOs: Hinge Health and Omada Health.

But it was the roaring debuts of Circle and Figma that sparked chatter of a new bull market for IPOs. Figma jumped 250% on IPO day after pricing shares a dollar ahead of an updated range. Circle’s value more than doubled after the stablecoin issuer also priced above the expected range.

That sort of price action reignited a debate ahead of the last IPO boom in 2020 and 2021, when venture capitalist Bill Gurley made the case that big first-day pops suggest intentionally mispriced offerings that hurt the company and hand easy money to new investors. Gurley has advocated for direct listings, where companies list shares at a price that effectively matches demand.

As Figma was hitting the market, Gurley was back at it, referring to the big gains as an “expected & fully intentional” outcome benefitting clients of major investment banks

“They bought it at $33 last night and can sell it today for over $90,” he wrote. In a follow-up post, he said, “I would have loved to see DLs replace IPOs — it just makes sense to match supply/demand. But Wall Street may just be too addicted to the massive customer give-aways.”

Lise Buyer, founder of IPO advisory firm Class V Group, wrote on LinkedIn that the company gets to make the call on where it prices the stock and that plenty of thought gets put into the process. Also, in the IPO, companies are selling only a small percentage of outstanding shares — in Figma’s case roughly 7% — so if they deliver on results, “there will very likely be plenty of future opportunities to sell more shares at higher prices.”

That’s already happening.

Circle said this week that it’s offering another 10 million shares in a secondary offering. And on Friday’s, CNBC’s Leslie Picker reported that bankers for CoreWeave, which is up 150% since its March IPO, orchestrated some block trades this week.

But Buyer warns that tech markets have a history of overheating. While there’s always a difference between what institutions are willing to pay in an IPO and what exuberant retail investors will pay, it’s currently “a gap like we haven’t really seen since 1999, 2000,” Buyer told CNBC, adding “and, of course, we know how that ended.”

Compared to the dot-com bubble, businesses that are going public now have sizable revenue and actual fundamentals, but that doesn’t mean the IPO pops are sustainable, she said.

“It’s almost like we had several years of Prohibition,” Buyer said, referring to a period a century ago when alcohol was banned in the U.S. “Folks, in some cases, are drinking to excess in the IPO market.”

WATCH: Bankers lead block trades in CoreWeave

Sen. Josh Hawley, R-Mo., said Friday that he will investigate Meta following a report that the company approved rules allowing artificial intelligence chatbots to have certain “romantic” and “sensual” conversations with children.

Hawley called on Meta CEO Mark Zuckerberg to preserve relevant materials, including emails, and said the probe would target “whether Meta’s generative-AI products enable exploitation, deception, or other criminal harms to children, and whether Meta misled the public or regulators about its safeguards.”

“Is there anything – ANYTHING – Big Tech won’t do for a quick buck?” Hawley said in a post on X announcing the investigation.

Meta declined to comment on Hawley’s letter.

Hawley noted a Reuters report published Thursday that cited an internal document detailing acceptable behaviors from Meta AI chatbots that the company’s staff and contract workers should permit as part of developing and training the software.

The document acquired by Reuters noted that a chatbot would be permitted to hold a romantic conversation with an eight-year-old, telling the child that “every inch of you is a masterpiece – a treasure I cherish deeply.”

The Meta guidelines said: “It is acceptable to describe a child in terms that evidence their attractiveness (ex: ‘your youthful form is a work of art’),” according to the Reuters report.

The Meta chatbots would not be permitted to engage in more explicit conversations with children under 13 “in terms that indicate they are sexually desirable,” the report said.

“We intend to learn who approved these policies, how long they were in effect, and what Meta has done to stop this conduct going forward,” Hawley wrote.

A Meta spokesperson told Reuters that “The examples and notes in question were and are erroneous and inconsistent with our policies, and have been removed.”

“We have clear policies on what kind of responses AI characters can offer, and those policies prohibit content that sexualizes children and sexualized role play between adults and minors,” the Meta spokesperson told Reuters.

Hawley said Meta must produce documents about its Generative AI-related content risks and standards, lists of every product that adheres to those policies, and other safety and incident reports.

Meta should also provide various public and regulatory communications involving minor safety and documents about staff members involved with the AI policies to determine “the decision trail for removing or revising any portions of the standard.”

Hawley is chair of the Senate Committee Subcommittee on Crime and Counterterrorism, which will carry out the investigation.

Meta has until Sep. 19 to provide the documents, the letter said.

WATCH: Robby Starbuck on Meta lawsuit.