Key Highlights

● The Nasdaq-100 closed at 29,402.51 on Thursday, October 29.

● The index stayed negative for October while the Dow and Russell 2000 gained.

● Alphabet closed at $283.82 after its worst day since its 2004 IPO.

● Futures fell after Amazon and Intel slid sharply in extended trading.

The index of the largest non-financial Nasdaq stocks fell hard on Thursday, leaving it nursing a loss for the month with one trading day left and two of its heaviest members in turmoil after the bell.

A rough close to a rough month

The Nasdaq-100 closed at 29,402.51 on Thursday, October 29, after a steep decline that tracked the broader Nasdaq Composite. The index had already been down for October as of a midday market snapshot, when it stood at 29,501.85, and it finished the session even lower. That leaves the index needing a powerful rally on Friday, the final trading day of the month, to avoid a monthly loss.

The contrast with other benchmarks is striking. The Dow and the Russell 2000 were both up for October at midday on Thursday. The Nasdaq-100 is the outlier, and the reason is concentration.

The heavyweights stumble

The Nasdaq-100 is dominated by a small group of giants, and several of them had difficult weeks. Alphabet (NASDAQ:GOOGL) was the biggest culprit on Thursday, closing at $283.82 after its worst day since its 2004 IPO. The Google parent missed Revenue and adjusted Earnings forecasts, posted negative free Cash Flow of $9.07 billion and kept its heavy Capital spending plan intact.

Microsoft (NASDAQ:MSFT) offered little relief. Despite a quarter that one report described as "a big cash-flow beat" and an encouraging cloud forecast, its stock finished roughly flat to lower on Thursday after jumping in after-hours trading the night before. Amazon (NASDAQ:AMZN) slid to $243.79 ahead of its report, Nvidia (NASDAQ:NVDA) edged lower and Intel (NASDAQ:INTC) fell in the regular session.

Software and cyber names pile on

The pain extended to the index's software and Cybersecurity members. Fortinet (NASDAQ:FTNT) tumbled to $139.10 after cutting its full-year service revenue forecast, and a brokerage downgraded the stock to Neutral. Palo Alto Networks (NASDAQ:PANW) and Zscaler (NASDAQ:ZS) were dragged into the selloff, with Zscaler Gapping down early before recovering some ground. Marvell Technology (NASDAQ:MRVL) sank after one media report said it was in advanced talks to acquire Lumentum (NASDAQ:LITE), talks neither company has confirmed.

A few bright spots

Meta Platforms (NASDAQ:META) bucked the trend, rising after an activist investor called it "incredibly undervalued" in a television interview, ending a five-session slide. KLA (NASDAQ:KLAC) held up among chip stocks, and Apple (NASDAQ:AAPL) was higher at midday. But gains from those names could not offset the weight of Alphabet's plunge. Just outside the index, Gen Digital (NASDAQ:GEN), which trades on the Nasdaq but is not a Nasdaq-100 member, soared and showed how a strong beat-and-raise quarter could still be rewarded, a reminder that Thursday's selling was targeted rather than indiscriminate.

Why October went wrong

Much of the month's weakness traces back to one question: are the giant AI spenders getting enough return for their money? One market strategist said that "markets are no longer rewarding companies simply for investing heavily in AI." With the Federal Reserve hiking in September and holding this week, and the 10-year Treasury Yield touching its highest level since 2002 around the start of the month, investors have also had less patience for richly valued growth stocks.

The Nasdaq-100 still holds a solid gain for 2026 as a whole, so October's setback has trimmed rather than erased its yearly advance.

What to watch

Friday may be ugly at the open. Nasdaq-100 futures slid in extended trading on Thursday evening after Amazon and Intel both fell sharply after hours. Amazon's fourth-quarter sales guidance midpoint missed consensus, and Intel's fourth-quarter forecast came in well below expectations. Traders will also digest the Employment Cost Index and Chevron (NYSE:CVX) and AbbVie (NYSE:ABBV) results before deciding whether the index ends October with a whimper.