AMD Joins $1 Trillion Club as Chipmakers Rally on AI-Driven Demand

Advanced Micro Devices (AMD) has crossed $1 trillion in market capitalisation for the first time, becoming the fourth US chipmaker to reach the milestone as its shares surged on growing investor confidence in AI-driven demand.

AMD shares rose 9.6% to a record $613.31 apiece on September 21, taking the chipmaker’s stock gains in 2026 to 185%. The rally comes as AMD expands beyond individual chips into complete AI computing systems and gains market share from Intel in CPUs used alongside GPUs for AI inference workloads. The broader semiconductor sector also rallied, with Intel gaining about 11.8%, Qualcomm 4.5%, and the Philadelphia Semiconductor Index rising 2.7%.

The rally reflects growing investor interest in AMD’s AI business as the chipmaker expands its portfolio beyond individual processors, where it is increasingly seen as NVIDIA’s closest rival in graphics processing units (GPUs).

The renewed interest comes after enthusiasm for chipmakers had cooled in recent months as investors questioned whether spending on AI infrastructure by hyperscalers could continue at its current pace. Higher oil prices linked to the US-Iran conflict and expectations that interest rates could remain elevated also weighed on the sector.

AMD has been expanding its AI portfolio beyond individual chips. The company is increasingly offering complete computing systems that combine processors, networking equipment and other hardware, putting it in more direct competition with NVIDIA’s full-stack AI infrastructure strategy.

Demand for central processing units (CPUs) used alongside GPUs in servers handling AI inference has also helped AMD gain market share from Intel.

Despite the strong stock-market performance, AMD’s valuation remains closely watched. The company was trading at around 41 times its 12-month forward earnings, below its 10-year average of 44 times but significantly above NVIDIA’s recent multiple of 16.3 times forward earnings.