By Britney Nguyen

On an intraday basis, AMD became the 14th U.S. company to see its market capitalization top $1 trillion

AMD's stock is rising Monday alongside shares of other companies that make central processing units for servers.

Shares of Intel, Advanced Micro Devices and other hardware stocks were storming higher on Monday in a show of intense investor appetite for the artificial-intelligence trade.

Arm Holdings' (ARM) U.S.-listed shares were up 15.4% in morning trading, while Intel's stock (INTC) was ahead 14.4%. Advanced Micro Devices' stock (AMD) was up 8.9%, putting it on track for a record close.

AMD shares traded as high as $615.99, a level that translated to a market capitalization above $1 trillion. Shares have since pulled back to $609.32 and need to close above $612.56 to finish in trillion-dollar territory, according to Dow Jones Market Data.

Only 13 other U.S. companies have crossed the $1 trillion mark. AMD shares have seen an extreme rally: The company was worth $255 billion at this point last year.

Arm, AMD and Intel are all in the business of making central processing units for artificial-intelligence servers. This corner of the chip market has seen momentum in recent months, driven in part by the proliferation of AI agents, or services that can act autonomously on behalf of users. And Meta Platforms' (META) Muse, a consumer-focused AI agent, is garnering buzz since launching earlier this month.

Meanwhile, the PHLX Semiconductor Index SOX is up 2.7%.

Another driver of AI stock momentum on Monday could be news from the last few days surrounding Anthropic and OpenAI, according to a note from Jeffrey Favuzza, an equities-trading analyst at Jefferies.

Anthropic announced Friday afternoon that it will work with consulting firm Accenture (ACN) to independently evaluate frontier AI models, or those deemed to be on the cutting edge. Both Anthropic and Accenture expect to invest at least $1 billion in the effort over the next five years, according to the company behind the Claude AI assistant. Under the agreement, Anthropic said embedded evaluators will have similar access as employees to assess model development and deployment.

The partnership comes after Anthropic CEO Dario Amodei published an essay earlier this month calling for a slowdown in the development of leading-edge AI models. Investors have generally gotten more concerned about AI safety.

The Wall Street Journal also reported Friday that Anthropic is planning to hold its initial public offering in November. The Journal noted that investors expect Anthropic's offering to raise up to $100 billion, while the New York Times reported Friday that the company could see up to $100 billion in annualized revenue by year-end.

Anthropic could share financial paperwork for its IPO in the coming weeks, the New York Times reported, citing people speaking on condition of anonymity. Reuters reported that Anthropic could release a new AI model before its IPO, as it faces steep competition with OpenAI after that company's launch of GPT-6 Astra.

Favuzza also pointed to a report from the Financial Times saying that OpenAI expects its revenue to jump almost 10 times, from $36 billion this year to $350 billion by the end of the decade, although it could also spend about $280 billion on computing power over that period.

Mizuho analyst Daniel O'Regan said in a note to clients that the headlines around both AI startups "reinforce expectations for sustained AI infrastructure spending."

Meanwhile, shares of networking provider Ciena (CIEN) were up 3.5% Monday morning after an upgrade by Evercore ISI analyst Amit Daryanani, who moved from an in-line rating to an outperform rating on the stock.

Daryanani said the company is "an attractive way to gain exposure to the optical networking space," which has become a bottleneck in the AI data-center buildout.

Ciena's offerings are "purpose built to address" the connectivity demands of AI data centers given the company's full focus on optical systems, Daryanani said in a Monday note to clients.

-Britney Nguyen

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09-21-26 1158ET