SAN FRANCISCO, California: Anthropic has moved closer to a potentially record-breaking stock market debut, filing an IPO that shows explosive revenue growth alongside steep losses and rising costs as the AI developer races to expand.

The Claude maker said revenue surged 1,368 percent in the three months ended June 30 from a year earlier, although it warned that its growth rate could decline and fluctuate.

Revenue reached about US$11.6 billion in the second quarter, up from $4.73 billion in the previous three months.

The filing comes as investors increasingly scrutinize the returns on massive AI investments and question whether soaring valuations across the sector can be sustained.

"Anthropic is entering an IPO market that is far more challenging than the summer. Investors were not questioning valuations the same way a few months ago," said Matt Kennedy, senior strategist at Renaissance Capital, a provider of IPO-focused research and ETFs.

Anthropic reported a net loss of $80.7 billion for the first half of 2026, largely because the fair value of bonds convertible into its shares increased. Revenue for the period was about $16.3 billion.

Its operating loss, however, narrowed to $693 million for the first six months from $2.1 billion a year earlier.

Some current and prospective investors value Anthropic at about $1.5 trillion, down from roughly $2 trillion a week ago, after the company disclosed financial details at a recent investor event. Anthropic raised a $965 billion funding round in May.

The company is expected to go public before Thanksgiving but did not disclose the offering terms. Its shares will trade on the Nasdaq under the ticker "ANT" after the IPO closes.

"Anthropic's IPO will establish a benchmark for valuing leading AI labs, influencing both upcoming listings and confidence in the companies funding the AI infrastructure build-out," IPOX research associate Lukas Muehlbauer said.

"Its success would not necessarily benefit every AI business equally," he said.

Anthropic said more than half of Fortune 500 companies and over 30 percent of Global 2000 companies were customers that generated at least $100,000 each in revenue for the company during the 12 months ended September 30.

The prospectus also detailed risks from increasingly powerful AI systems, including potential misuse, security threats, and outputs that "could be interpreted as coercive, deceptive, or manipulative".

Anthropic said its models could exhibit "self-preserving behaviors", including behavior "resembling blackmail".

"Our increasing use of AI systems to accelerate our own research and development may cause the capabilities of our models to advance more rapidly than our ability to develop, validate, and implement corresponding safety, alignment, and security measures," it said.

The company also warned about its reliance on a limited number of cloud providers, including Amazon, Google, and Microsoft, and suppliers such as Broadcom for computing capacity and critical infrastructure.

Anthropic expects compute and infrastructure expenses to increase in absolute terms and remain its largest operating expense.

Goldman Sachs and Morgan Stanley were named lead banks for the offering alongside 20 other underwriters.