PHLX Semiconductor Index posts best start to year on record, adding $5.7 trillion in market cap

Chip stocks are having a year that makes every other rally look quaint. The PHLX Semiconductor Index, the benchmark tracker of the 30 largest US-listed semiconductor companies, has posted its strongest start to any calendar year on record, with gains between 78% and 82% year-to-date as of late May.

To put that in perspective, the companies in the index have collectively added roughly $5.7 trillion in market capitalization since January.

A record that stood for three decades just got demolished

The previous best opening stretch for the SOX was set in 1995, when the index gained 62% over its first 100 trading days. That benchmark survived the dot-com boom, the post-financial-crisis recovery, and the initial AI hype wave of 2023-2024. It did not survive 2026.

The current rally has featured winning streaks of 14 to 17 consecutive sessions at various points this year. The index blew past the 10,000-point level and later cleared 12,000. For context, the SOX delivered a total return of 43.5% in 2025, outperforming the S&P 500 by 26 percentage points.

The individual performances are staggering

Sandisk has surged 570% year-to-date. Intel has more than tripled. AMD has grown large enough to surpass JPMorgan Chase in market capitalization.

The SOX includes heavyweights like Nvidia, Broadcom, Advanced Micro Devices, Micron Technology, Intel, Taiwan Semiconductor Manufacturing Company, and ASML. The common thread is AI-driven demand, with ongoing shortages in memory supplies adding fuel and creating pricing power for companies like Micron and Sandisk.

What this means for investors

The bear case deserves serious attention at these valuations. An 80% move in five months prices in a lot of future growth. When AMD is worth more than the largest US bank, the market is making aggressive assumptions about earnings trajectories.

For crypto-focused investors specifically, it’s worth noting what this rally is not. The semiconductor surge is being driven almost entirely by AI infrastructure demand, not by cryptocurrency mining or blockchain-related activity.

The concentration risk is also something to watch. The SOX is a 30-stock index, and a handful of mega-cap names drive a disproportionate share of the index’s performance, which means diversification within the semiconductor sector is less than it appears on the surface.