SANTA CLARA, California: Advanced Micro Devices crossed US$1 trillion in market value for the first time on September 21, as its shares jumped to a record high amid investor enthusiasm over the chipmaker's growing role in artificial intelligence computing.

AMD shares were last up 9.6 percent at $613.31. The company became the fourth U.S. chipmaker to surpass a $1 trillion valuation, following Nvidia, Broadcom and Micron.

Nvidia first crossed the threshold in 2023 and is now the world's most valuable company, with a valuation exceeding $5 trillion.

"Money is moving back into the AI trade," said Thomas Hayes, chairman at Great Hill Capital LLC in New York.

Enthusiasm for chipmakers had cooled in recent months as markets scrutinized AI spending by hyperscalers. Higher oil prices linked to the U.S.-Iran conflict and expectations that interest rates would remain higher for longer also added pressure.

Hayes said investors now believe AI is the only area that can work in a Federal Reserve-induced economic slowdown. "AMD is representative of that."

Other chip stocks also rallied on September 21. AMD rival Intel jumped about 11.8 percent, while Qualcomm gained 4.5 percent. The broader Philadelphia semiconductor index rose 2.7 percent to its highest level in more than a month.

AMD has accelerated its AI product launches and expanded beyond individual chips to complete systems that combine processors, networking equipment, and related hardware as it competes with Nvidia.

Demand for central processing units used alongside graphics processors in servers handling inference has also helped AMD gain market share from Intel.

Last month, AMD forecast quarterly revenue above Wall Street estimates, although the outlook fell short of elevated investor expectations.

AMD shares have surged 185 percent in 2026, far exceeding the 15.8 percent gain in the tech-heavy Nasdaq and placing the stock among the top performers in the S&P 500.

AMD last traded at about 41 times its 12-month forward earnings, below its 10-year average of 44 but well above Nvidia's recent multiple of 16.3 times forward earnings.