Chip stocks fall for a seventh straight day, leaving the semiconductor index in bear-market territory

U.S. chip stocks fell for a seventh straight session on Thursday, Oct. 15, and the PHLX Semiconductor Index closed more than 20% below its record, the line investors commonly use to mark a bear market.

Seven sessions, 12% lower

The index, widely known by its ticker SOX, closed at 11,581.22, down 103.16 points, or 0.9%, from Wednesday. It had been down far more. At its low of the day the index stood at 11,171.53, about 4.4% under Wednesday's close, before buyers won back most of that ground.

The streak began after an Oct. 6 close of 13,217.82. Since then the index has dropped about 12.4%, and it now sits about 20.9% below its record close of 14,634.72 on June 22. A 20% fall from a peak is the usual rule of thumb for a bear market.

The damage has come in bursts. Three of the seven declines were smaller than 1%, but the index fell 3.4% on Oct. 8, 2.7% on Oct. 12 and 4.3% on Wednesday, Oct. 14, the worst day of the run.

Seven straight losses tie the index's longest losing run in daily closing data going back to October 2016. The most recent one came in May 2025, when the SOX fell every session from May 15 through May 23.

Equipment makers among the hardest hit

Makers of chipmaking machinery were among Thursday's heaviest decliners. Applied Materials dropped 3.7% to $430.01, Lam Research fell 3.3% to $277.46 and KLA lost 2.4% to $174.46. Applied Materials is now down about 18.9% from its Oct. 6 close, Lam about 16.9% and KLA about 11.6%. Those companies sell into chipmakers' factory budgets, so their shares tend to swing with investors' expectations for how much the industry will spend on new capacity.

Nvidia fell 1.8% to $217.23, leaving it about 9.2% below where it closed on Oct. 6. A strong quarterly report from Taiwan Semiconductor Manufacturing on Thursday was not enough to stop the slide, as Investor's Business Daily noted; the contract chipmaker's U.S.-listed shares fell 1.8% to $422.25, about 12.5% below their Oct. 6 close.

Micron Technology went the other way, rising 1.9% to $931.24. Even so, the memory maker finished Thursday about 9.5% below its close on Friday, Oct. 9.

What is behind the selling

Reuters tied the slide to rising bets on an interest-rate increase and to concern about the cost of the artificial intelligence buildout. By its count, U.S. chip stocks had lost $1.64 trillion in market value over the six sessions before Thursday.

CNBC reported that a slide in AI-related stocks, especially memory-chip makers, has weighed on the market this week amid jitters about competition from China, and that investors have grown worried that technology companies are borrowing too much to fund AI infrastructure. Asian markets sold off sharply on Thursday as investors soured on AI plays over financing, rising competition and the possibility of a chip glut in a few years, the network said.

Thursday also brought hot inflation data. The Bureau of Labor Statistics said its producer price index for final demand rose a seasonally adjusted 1.3% in September, the largest monthly increase since March 2022, and was up an unadjusted 6.3% from a year earlier.

Bond yields fell anyway. The Treasury Department's daily par yield curve put the 10-year yield at 5.1% on Thursday, down from 5.19% on Wednesday, and the two-year yield at 4.77%, down from 4.82%.

The rest of the market rose

The chip selling did not pull down the broader market. The Dow Jones Industrial Average rose 556 points, or 1.1%, to 52,177.69. The S&P 500 gained 0.3%, and the Nasdaq Composite, where many chip stocks trade, edged up 0.08% to 26,713.03. The split suggests investors were moving money away from technology shares rather than out of stocks altogether.