Sam Altman’s OpenAI allowed employees to cash out a whopping $6.6 billion in sales of shares last October, according to a report.

More than 600 current and former workers participated and were allowed to sell up to $30 million in shares each as part of a financing round, the Wall Street Journal reported Monday, citing people familiar with the matter.

About 75 employees maxed out their sales and received the full $30 million, the report said.

OpenAI bars employees from selling shares within their first two years of employment. The employee share sale followed a period of massive growth at the San Francisco-based company, which launched ChatGPT in late 2022.

The company previously barred workers from selling more than $10 million in shares at a time in its tender offers, but tripled the cap to $30 million last year due to surging demand from outside investors, according to the Journal.

The old $10 million limit had reportedly irritated some of OpenAI’s top researchers, who would otherwise have been able to sell shares worth far more than that.

OpenAI was valued at $852 billion as of March – an astronomical increase compared to three years prior, when a tender offer pegged its valuation at about $29 billion.

Altman’s firm has remained at the forefront of the AI race despite fierce competition from rivals like Dario Amodei’s Anthropic and Elon Musk. The latter, who cofounded OpenAI alongside Altman, is currently suing the company for allegedly violating its nonprofit mission.

The employee share sale occurred as both OpenAI and Anthropic race to go public as soon as this year. Both are expected to be among the largest IPOs in Wall Street’s history.

OpenAI did not immediately return a request for comment.