The S&P 500 is up roughly 12% in 2026, but its best-performing components have delivered extraordinary, triple-digit gains, with artificial intelligence (AI) infrastructure and memory narratives driving a remarkable stock market rally.
Notably, SanDisk (NASDAQ: SNDK) has emerged as the number one stock, leading with a 574% year-to-date (YTD) gain driven by surging investor enthusiasm for flash memory and storage technology used in data-center workloads.
Moderna (NASDAQ: MRNA), which ranks number two, enjoys a 388% return in the same period. The biotechnology company’s extraordinary move came after positive late-stage results for its experimental melanoma treatment, which sent the stock flying 140% on August 19.
Technology and semiconductor stocks dominate the S&P 500
Semiconductor and tech stocks dominate the top. For example, Dell Technologies Inc. (NYSE: DELL) has gained 248%, now expected to reach a new all-time high in the next 12 months. Meanwhile, Micron Technology (NASDAQ: MU) has climbed 229.26%, with analyst confidence in the memory industry growing.
Similarly, Seagate Technology (NASDAQ: STX) rose 193%, followed by Marvell Technology (NASDAQ: MRVL) at 163%, Western Digital (NASDAQ: WDC) at 146%, and Intel (NASDAQ: INTC) at 146%. Intel is especially notable as insider sales confirm internal confidence in the firm’s trajectory.
Likewise, among the top ten S&P 500 stocks 2026 are Lumentum Holdings (NASDAQ: LITE), which is up 120%, and Marathon Petroleum (NYSE: MPC), having also gained 120%. Lumentum has benefited greatly from the massive demand for the company’s 1.6-terabit optical transceivers, and management is now focused on a new North Carolina facility, targeting a $75 billion market.
Marathon itself has also crushed Wall Street expectations in its Q2 2026 report on August 4, benefiting from the Middle-Eastern conflicts, in particular the disruptions in the Strait of Hormuz, which have allowed the company’s Q2 profit to jump almost fourfold.
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