Semiconductor Index Falls 12.15% as S&P 500 Slides

By Sophie Lindqvist

The PHLX Semiconductor Index fell 12.15%, from 10,688.80 to 9,390.25, in the week ending November 6, 2026. The S&P 500 lost 2.68% over the same Friday-to-Friday span, closing at 7,376.86 versus 7,580.07 a week earlier. That marked its worst such week since the tariff-driven correction ending April 4, 2025.

What made the November decline qualify as the worst since April?

That label needs context. During the week ending April 4, 2025, the S&P 500 fell from 5,580.94 to 5,074.08, a 9.08% correction. November's decline was far smaller.

Only the S&P 500 can claim the worst-since distinction. The weeks ended May 23, 2025 and June 5, 2026 produced losses of 2.61% and 2.59%, narrowly avoiding a larger weekly drop.

The four-week run began with three smaller declines:

• Week ending October 16: S&P 500 down 1.95%.
• Week ending October 23: S&P 500 down 0.47%.
• Week ending October 30: S&P 500 down 0.57%.

The index closed 5.65% below its October 6 record close of 7,818.93. Four consecutive losses establish the direction, but not a collapse on the scale of April 2025.

Was the selloff broad or concentrated in technology?

The Nasdaq Composite fell 3.37% for its own fourth consecutive weekly loss. Its performance was not a new weekly low, however: the week ending October 16 produced larger declines of 4.48% for the Composite and 5.49% for the Nasdaq-100.

The report therefore assigns the worst-since weekly label only to the S&P 500. The distinction matters because semiconductors and AI hardware suffered much steeper losses than the broader index.

The Technology Select Sector SPDR fell 7%, while the SPDR energy sector fund fell 11%. The Dow, tracked by the SPDR Dow Jones Industrial Average ETF Trust, slipped only 0.94% to 51,285.73.

On Friday, the Dow lost 237.33 points, or 0.46%, while the S&P 500 rose 0.31% and the Composite gained 1.09%. That split suggests selling stayed concentrated in AI hardware and energy rather than becoming an indiscriminate market liquidation.

Thursday, November 5, supplied most of the damage. The report links the S&P 500's 4.36% decline to heavy selling in AI stocks after midterm results. It was the index's worst day since the April 2025 crash.

What does concentration mean for index funds?

The Invesco QQQ Trust fell 4.98% to $656.10. The State Street SPDR S&P 500 ETF Trust lost 2.7%, moving from $755.72 to $735.29, but retained much of the same AI exposure.

SPY's March 2026 fact sheet put NVIDIA at 7.58% of the fund. Because the S&P 500 weights companies by market value, large AI constituents can move a fund widely regarded as diversified.

The source presents an equal-weight S&P 500 fund as a way to reduce that concentration. It assigns NVIDIA the same weight as every other constituent, making the fund less sensitive to swings in individual chip stocks.

The article also links a separate report on seven suppliers serving AI power-and-cooling needs. It provides no supplier names, capacity figures or revenue estimates, so the reference adds no operating evidence to the market case.

Can jobs and inflation explain the valuation pressure?

Employers added 165,000 jobs in October, far above the expected 65,000. September's gain was revised to 60,000, while unemployment fell to 4.1%. Traders raised the probability of a December rate hike to 78% from 70%.

The report links stronger hiring to continued wage and inflation pressure, giving the Federal Reserve reason to raise rates. Higher discount rates reduce present valuations, especially for technology companies dependent on profits expected years ahead.

October's Consumer Price Index arrives Tuesday, November 10, at 8:30 a.m. ET. NVIDIA reports fiscal third-quarter results after the close on November 17. A hot inflation reading would increase the likelihood of a hike, while strong NVIDIA guidance could help stabilize chip stocks.

Neither outcome is guaranteed by the current data. The report establishes a riskier rate backdrop, but it does not quantify how much of the semiconductor decline came from rates rather than earnings expectations.

What are strategists claiming?

Keith Lerner, chief investment officer at Truist Advisory Services, said: “AI is still the main theme of this bull market.” He also described the selloff as a likely longer-term buying opportunity.

Adam Turnquist, chief cross-asset strategist at LPL Financial, called the week “a knee-jerk reaction to the midterms.” Their views treat the decline as a correction within the existing AI investment trend rather than a confirmed change in that trend.

The report describes SPY's long-term trend as intact, citing its 7.83% gain for the year. That is a backward-looking performance claim, not proof that AI valuations or future earnings will hold.

What would break the recovery view?

The stated recovery case weakens if the S&P 500 closes November 13 below 7,376.86, producing a fifth consecutive weekly loss, and NVIDIA's report fails to stop the decline. Both conditions would undermine the argument that recent losses merely reflect election-driven selling.

The report supplies no shipment, capacity, process-node or chip-pricing figures. Its signal therefore concerns market positioning, not evidence of changing semiconductor demand.

For chip investors, November 17 is the near-term test: can NVIDIA guidance stabilize semiconductor shares after a 12.15% sector-index fall, or will a firm CPI print magnify their dependence on distant profits?