Tech Sold Off in October, but the Dow and the Equal-Weight S&P 500 Told a Different Story

The Nasdaq fell 2.60% on October 22, 2026, as renewed doubts about artificial intelligence drove a selloff in technology shares. The S&P 500 slid 1.21% over the same session, while the Dow Jones Industrial Average rose 0.02%. Reuters

The difference between the three indexes is the useful part. The Dow is price-weighted, meaning each stock counts according to its share price rather than the size of its company, and it holds few of the mega-cap names that dominate the Nasdaq. The S&P 500 and Nasdaq are cap-weighted, so each company counts in proportion to its total market value. When a handful of giant tech firms fall, those two benchmarks feel it most.

The reversal was fast. On October 21, the Dow gained 0.69%, the S&P 500 added 0.58% and the Nasdaq rose 1.05%, with results from SpaceX and Super Micro lifting sentiment around AI-linked stocks. Reuters Two sessions later, the same complex was the pressure point. Earlier in the month, on October 8, the S&P 500 and Nasdaq both finished lower as Big Tech and semiconductor stocks struggled, while the Dow ended higher. MarketWatch Three episodes in three weeks shared the same shape: semiconductors and megacap software moved the headline indexes while the Dow lagged or held.

Friday, October 23, closed the week lower. The Dow fell 1.23% and the S&P 500 fell 0.52%. Reuters The technology sector posted a 0.35% gain that day, so the broad decline came from elsewhere in the market.

For anyone reading sector returns closely, that split is worth noting. The group at the center of the AI debate was not the weakest part of the market on the final session of the week.

The equal-weight view tells a different part of the story. Equal weighting gives each company roughly the same influence on the index, regardless of its size. The S&P 500 Equal Weight Index closed at 8,772.37 on October 23, down 0.78% on the day, against the S&P 500's 0.52% decline. Its year-to-date price return (the change since the start of 2026) stood at 8.57%, its one-month return at -4.99%, its three-month return at -2.29%, and its one-year return at 13.50%. S&P Dow Jones Indices Because each constituent carries roughly the same weight, this index moves closer to the typical stock than to the handful of names that drive cap-weighted returns.

In my view, a single day's move establishes little. A slide of roughly five percent over a month, though, suggests the pullback has reached well beyond the largest technology names.

That fits an earlier pattern. In July 2026, the equal-weighted S&P 500 gained 1.1% and outperformed the Nasdaq-100 by 7.6 percentage points. MarketWatch via Morningstar By August 23, CNBC reported that the equal-weight S&P 500 was leading the 2026 market. CNBC The breadth trade that carried the index in midsummer has since given back ground, and the most recent month is where that reversal shows.

For savers and investors, the practical question is exposure. A cap-weighted index fund and an equal-weight product can both carry the S&P 500 label and still diverge meaningfully when a few large companies lead or lag. The latest data show that divergence running in both directions this year. Checking the weighting method is worth doing before assuming two products behave the same way.

The skeptical reading is also the sober one. Renewed AI doubts explain a sharp move on one day, but this is a handful of sessions, not a trend. The depth of the selloff, its breadth across the market, and whether the Friday tech-sector gain marks a turn will only become clear over a longer window. What comes next is still open.