Tech Stocks Fell on AI Worries, but the Dow Held Up

Tech stocks fell sharply on October 22, 2026, as doubts about artificial intelligence (AI) came back. The Nasdaq dropped 2.60%. The S&P 500 fell 1.21%. The Dow Jones Industrial Average rose 0.02%. Reuters

Why did three major indexes move so differently? An index is a basket of stocks that stands in for the market as a whole. The Nasdaq and the S&P 500 weight each company by its size, so the biggest firms move the index the most. Think of it like a class average where the best-funded students count for far more than everyone else. The Dow works differently. It is price-weighted and holds few of the giant tech companies, so a tech selloff hits it less.

The gap between the three indexes is the story, in my view. It shows how much one group of companies can steer the headline numbers.

The reversal came quickly. On October 21, the Dow gained 0.69%, the S&P 500 added 0.58%, and the Nasdaq rose 1.05%. Results from SpaceX and Super Micro lifted sentiment around AI-linked stocks. Reuters Two sessions later, that same group was the source of the pressure.

Earlier in October, on October 8, the S&P 500 and Nasdaq both closed lower as big tech and chip stocks struggled. The Dow finished higher. MarketWatch

That makes three episodes in three weeks with the same pattern. Chip makers and large software companies pulled the headline indexes around, while the Dow lagged or held steady.

On Friday, October 23, the week ended lower. The Dow fell 1.23%, and the S&P 500 fell 0.52%. Reuters Technology stocks still rose 0.35% that day, so the broad decline came from other sectors. A sector is a group of companies in the same line of business, such as tech, banks, or energy.

To me, that split is worth noticing. The companies at the center of the AI debate were not the weakest part of the market on the last trading day of the week.

A different index tells another part of the story. The S&P 500 Equal Weight Index treats every company in the S&P 500 about the same, no matter how large it is. It closed at 8,772.37 on October 23, down 0.78% on the day. The S&P 500 fell 0.52%. S&P Dow Jones Indices

Its longer returns were also reported. Year to date, meaning since the start of 2026, it was up 8.57%. Over one month it was down 4.99%. Over three months it was down 2.29%. Over one year it was up 13.50%.

Because each company carries roughly the same weight, this index follows the typical stock more closely than the few giants that drive the regular S&P 500. One day tells us very little. A slide of about 5% over a month, though, suggests the pullback has spread well beyond the largest tech names.

This fits an earlier pattern. In July 2026, the equal-weight S&P 500 rose 1.1% and beat the Nasdaq-100 by 7.6 percentage points. A percentage point is simply the gap between two percentages. MarketWatch via Morningstar By August 23, CNBC reported that the equal-weight S&P 500 was leading the market in 2026. CNBC The gains that carried the index in midsummer have since given back some ground, and the most recent month shows that reversal.

For savers and investors, the practical question is what you actually own. Two funds that both say "S&P 500" can perform quite differently when a few big companies lead or lag. This year's numbers show that difference running in both directions. Before you assume two products do the same thing, check how each one weights its companies.

The cautious reading is also the more honest one. Renewed AI doubts explain a sharp move on one day, but a handful of sessions does not make a trend. How deep this selloff goes, how widely it spreads, and whether Friday's tech gain signals a turn will only be clear over a longer period. What happens next is still open.