Sandisk (NASDAQ: SNDK) has been by far the best-performing S&P 500 (SNPINDEX: ^GSPC) stock in 2026 with a 544% year to date gain as of the market close on Aug. 13. Sandisk is followed by Dell Technologies, Seagate Technology, Micron Technology (NASDAQ: MU) -- which now has a market cap of more than $1 trillion -- Intel, Western Digital, Marvell Technology, Hewlett Packard Enterprise, Lumentum, and Advanced Micro Devices. So the 10 best-performing S&P 500 stocks are all tech stocks with significant exposure to the boom in artificial intelligence (AI) spending.
Given that concentration, you may think that large-cap tech stocks are driving the market to new heights. But surprisingly, small-cap stocks are outperforming mid-, large-, and mega-cap stocks in 2026 -- as well as the S&P 500 and Nasdaq-100 -- which is the largest non-financial companies by market cap in the Nasdaq Composite (NASDAQINDEX: ^IXIC) Missed Nvidia in 2009? This Rare Signal Is Flashing Again.
In 2009, a "Double Down" signal flashed for a little-known chipmaker called Nvidia. For the first time in years, that same "Total Conviction" signal is flashing for a company 1/100th the size of Nvidia. Continue » Here's why the Vanguard Morningstar Small-Cap ETF (NYSEMKT: VB) presents one of the best ways to invest in small-cap stocks, and why the exchange-traded fund could be a buy now.
In 2022, the S&P 500 fell 19%, and the Nasdaq-100 fell 33%, as investors questioned valuations and digested inflationary pressures. But on Nov. 30, 2022, OpenAI released ChatGPT for free. What has followed has been nothing short of paradigm-shifting momentum in the U.S. stock market -- driven largely by artificial intelligence (AI), the technology sector, and mega-cap growth stocks.
The gains were so large that Bank of America analyst Michael Hartnett popularized the term "Magnificent Seven" in 2023 to describe seven tech-fueled mega-cap growth stocks -- Nvidia (NASDAQ: NVDA), Apple, Alphabet, Microsoft, Amazon, Meta Platforms, and Tesla. The AI-driven rally has expanded significantly beyond the Magnificent Seven, with the biggest winners in 2026 largely companies benefiting from record AI capital spending -- from memory chip stocks to networking companies to semiconductor equipment makers. Despite the rallies in tech stocks like Sandisk and Micron, there has been a slowdown in the mega-cap dominance.
In fact, Nvidia and Amazon are the only Magnificent Seven stocks that are outperforming the S&P 500 year to date -- and Meta Platforms and Tesla have declined. Big gains in semiconductor stocks have certainly contributed to strong 2026 performances in the S&P 500 and Nasdaq-100. But dig deeper, and there's an equally interesting force at play -- which is the rebound in mid- and small-cap stocks.
Extract — continue reading at the source.
