OpenAI overtakes Elon Musk's SpaceX to become the most valuable startup

OpenAI, the developer of ChatGPT, has been valued at $500 billion (approximately 73.8 trillion yen), making it the most valuable startup in the world, surpassing Elon Musk's space development company, SpaceX.

OpenAI Completes Share Sale at Record $500 Billion Valuation - Bloomberg
https://www.bloomberg.com/news/articles/2025-10-02/openai-completes-share-sale-at-record-500-billion-valuation

OpenAI overtakes SpaceX after hitting $500bn valuation
https://www.ft.com/content/f6befd14-6e8e-497d-98c9-6894b4cca7e4

OpenAI wraps $6.6 billion share sale at $500 billion valuation
https://www.cnbc.com/2025/10/02/openai-share-sale-500-billion-valuation.html

According to Bloomberg and other reports, OpenAI has signed an agreement to allow employees to sell their company stock, and has sold shares to investors such as SoftBank Group, Thrive Capital, Dragoneer Investment Group, MGX, and T. Rowe Price. This transaction values OpenAI at $500 billion (approximately 73.8 trillion yen).

This makes OpenAI the most valuable startup, surpassing SpacX, which has a valuation of $400 billion (approximately 59.1 trillion yen).

OpenAI had authorized employees to sell up to $10.3 billion (approximately 1.52 trillion yen) of stock, but only $6.6 billion (approximately 974 billion yen) of stock was actually sold. The source noted that 'the low participation rate in the transaction reflects employee confidence in OpenAI's long-term prospects.' The source also said, 'Investors remain very interested in purchasing OpenAI shares.'

Elon Musk, one of OpenAI's earliest investors, filed a lawsuit against OpenAI and Apple in August 2025, alleging that 'Apple and OpenAI are monopolizing the market and controlling it to prevent innovators like X and xAI from competing.' Furthermore, in September 2025, a new lawsuit was filed alleging that 'OpenAI unfairly poached employees to obtain xAI's trade secrets.'

Elon Musk sues Apple and OpenAI, claiming damages for unfairly lowering the rankings of apps like Grok in the App Store rankings - GIGAZINE

by Elon Musk

In response, OpenAI asked a federal judge to dismiss Musk's lawsuit, saying, 'We will fight back against Elon's harassment tactics. This is harassment disguised as a lawsuit. OpenAI does not need or want any trade secrets.'

Today we responded to Elon's latest harassment tactic dressed up as a lawsuit. OpenAI doesn't need or want anyone's trade secrets. We will protect our employees and won't be intimidated by his attempts to bully them. https://t.co/N4E0reaRF3

— OpenAI Newsroom (@OpenAINewsroom) October 2, 2025