Artificial intelligence company OpenAI has become the world’s largest startup after reaching a $500 billion valuation in a secondary share sale. 

Citing anonymous sources, Bloomberg reported on Thursday that current and former OpenAI employees sold $6.6 billion in stock to investors including Thrive Capital, SoftBank Group Corp., Dragoneer Investment Group, Abu Dhabi’s MGX and T.Rowe Price. 

The investment round boosted OpenAI's valuation to $500 billion, leapfrogging Elon Musk’s startup SpaceX, which has a market capitalization of about $400 billion. The company also dwarfed startups ByteDance and Anthropic, which are valued at $220 billion and $183 billion, respectively. 

The deal not only shows excitement around AI, but also a growing overlap between AI and blockchain, with capital flowing into the technologies increasingly viewed as the next pillars of digital infrastructure. 

OpenAI and crypto companies

At $500 billion, OpenAI towers over crypto’s biggest players. According to Google Finance, Coinbase, the largest publicly traded crypto exchange, has a market capitalization of about $89 billion.

Even the most promising crypto companies, including Ripple, Circle and Binance, have not broken past the $100 billion barrier.

However, with stablecoins gaining traction worldwide, issuer Tether might be the crypto company closest to rivaling OpenAI’s market cap.

On June 7, Artemis CEO Jon Ma claimed that if Tether were to go public, it would have a valuation of $515 billion, making it the 19th-largest public company. 

Tether CEO Paolo Ardoino responded to Ma, saying that while $515 billion is a “beautiful number,” he considered this “a bit bearish” given their Bitcoin and gold treasury. He also said that there was “no need” for Tether to go public. 

Source: Paolo Ardoino

AI agents to be the biggest stablecoin users

As AI and stablecoins both enhance the development of digital infrastructure, some say that there will be synergies between the two.

On Sept. 3, Galaxy Digital CEO Mike Novogratz said that AI agents will be the biggest users of stablecoins

Novogratz’s predictions may have already started to take shape, as analysts have recently linked stablecoin transactions to bots. On Wednesday, CEX.io Research said that over 70% of stablecoin transactions in the third quarter of 2025 are linked to bot activity

Novogratz’s Galaxy Digital has also been active in the AI business. On Aug. 15, the company secured a $1.4 billion loan to fast-track its Texas Helios AI datacenter.

The company expects the data center to earn over $1 billion annually, providing physical infrastructure for CoreWeave’s AI and high-performance computing (HPC) operations. 

Related: Over 70% of stablecoin transactions in Q3 linked to bots, report finds

Growing dangers of AI development

While AI continues to grow, Akash founder Greg Osuri has said that its energy requirements will become so intense that current energy grids will be unable to keep up.

At Token2049 in Singapore, Osuri told Cointelegraph that AI may soon need nuclear power to sustain training models. He also called for more sustainable approaches, such as decentralized AI training. 

Magazine: AI is good for employment says PWC — Ignore the AI doomers: AI Eye