NEW YORK — Semiconductor stocks closed the first half of 2026 with their strongest performance on record as investors continued to pour money into companies tied to artificial intelligence infrastructure, pushing chip indexes and several major chipmakers sharply higher.
The Philadelphia Semiconductor Index, a widely followed benchmark for the sector, gained about 94% in the first half of the year, marking its second-best first-half performance since its creation in 1994, behind only the dot-com era surge in 2000, according to market data cited by analysts.
The rally was driven by demand for semiconductors used in artificial intelligence systems, including chips for data centers, memory products and advanced computing infrastructure. Increased capital spending by large technology companies building AI capacity has supported expectations for continued demand across the semiconductor supply chain.
Several chip companies recorded outsized gains during the period. Memory chip maker Micron Technology was among the strongest performers, while Intel and Marvell Technology also posted significant increases, according to market reports.
The sector’s rise also increased the weight of semiconductor companies in broader U.S. equity markets. Chip stocks accounted for a record share of the S&P 500, reflecting the growing influence of artificial intelligence-related companies on index performance, according to market analysis.
Investors have focused on the expansion of AI infrastructure spending by major cloud and technology companies, which has boosted demand for processors, high-bandwidth memory and semiconductor manufacturing equipment. European and Asian chip-related companies also benefited from the global AI investment cycle, with technology stocks leading gains in several regional markets.
The gains came as some investors shifted attention toward hardware suppliers after earlier enthusiasm around AI software companies. Analysts have pointed to strong earnings expectations and supply constraints in certain semiconductor segments as factors supporting valuations.
Market participants have also monitored risks surrounding the pace of AI investment, semiconductor valuations and broader economic conditions. The rapid increase in chip shares has raised questions among some investors about whether future earnings growth will match elevated expectations, though the companies and sectors involved have continued to report strong demand trends.
The semiconductor industry enters the second half of 2026 with investor focus remaining on AI-related demand, corporate spending plans and upcoming earnings reports from major chip companies.
