Chip Stocks Didn't Fall on Chip News This Week. They Fell on a 19-Year High in the 30-Year Treasury Yield.

Semiconductor stocks sold off hard this week. The PHLX Semiconductor Index dropped about 5% on Tuesday and fell another 2% on Wednesday, and it now sits about 20% below the record it set on June 22.

A slide like that usually follows bad news. The unusual part is that there wasn't any -- at least not from the chip companies. The only company in the index that reported results this week, Analog Devices (NASDAQ:ADI), delivered records -- and told investors to expect a record fourth quarter on top of them.

Most of the pressure came from outside the sector: a bond market pushing long-term borrowing costs to two-decade highs, with rising oil prices piling on. On Tuesday, the yield on the 30-year U.S. Treasury bond topped 5.33%, its highest level since June 2007, according to CNBC.

For growth stocks whose valuations rest on profits years into the future, a yield like that is a problem all by itself.

Image source: Getty Images.

Two ugly sessions

Tuesday was the heavy one. The semiconductor index fell from 12,621 to 11,992, a decline of about 5%, with the selling reaching from the memory names to the artificial intelligence (AI) chip leaders.

Advanced Micro Devices (NASDAQ:AMD) fell about 4% on Tuesday and nearly as much on Wednesday. Micron Technology (NASDAQ:MU) dropped about 7% on Tuesday. Even Nvidia (NASDAQ:NVDA), the sector's biggest company, lost ground both days, though it held up better than most.

Wednesday's follow-through took the index down to 11,738. The two sessions together erased about 7% of the sector's value -- and this wasn't even the year's roughest stretch, since the index fell more than 10% in a single session back in early June.

And the run that preceded the slide is worth keeping in view. The index ended 2025 at 7,083. Even now, it is up about 66% in 2026.

The selling tracked the bond market

The 30-year Treasury yield has been climbing on worries that have nothing to do with semiconductors. The U.S. fiscal deficit hit $432.3 billion in July, its highest monthly total since March 2021, pushing the fiscal year's shortfall to nearly $1.8 trillion. Inflation remains above the Federal Reserve's 2% target, and rising oil prices have added to the worry. In short, investors are demanding more to lend the government money for 30 years than they have at any point since 2007.

To be fair, the day-to-day fit between yields and chip prices is loose. The 30-year first pushed into 19-year-high territory on Monday, and chip stocks rose that session. Then on Wednesday, the Treasury Department said it would double the size of its debt repurchases, the 30-year yield eased back to about 5.18% -- and chip stocks fell anyway.

The daily wiggles, I'd argue, aren't really the point. The level is. As of this writing, the 30-year is back above 5.2% and climbing again. Wherever the top tick lands, long-term money now costs more than it has in almost two decades.

Why does that matter for chip stocks in particular? A stock trading at a high price-to-earnings ratio is a claim on earnings that arrive years from now. When a Treasury bond pays more than 5% with no default risk, those faraway earnings are worth less today. The stocks with the most of their value parked in the future have the most to lose.

Multiples, sorted

Of course, the math doesn't hit every chip stock equally. Nvidia trades at about 33 times earnings, and about 22 times the profit analysts project for the year ahead. Those are big numbers, but they sit on revenue that grew about 71% over the past 12 months. AMD, near $465 as of this writing, costs about 42 times the year-ahead projection, with far more of its value resting on results that haven't arrived yet.

And Micron trades at about 21 times earnings but only about 6.5 times expected earnings. Investors already doubt the memory boom's staying power, so its problem is the cycle, not the discount rate.

Sure, Tuesday's selling was indiscriminate -- every one of those stocks fell, whatever its valuation. Panicked days usually are. But if long rates stay near 2007 levels, I'd expect the sorting to continue, with the richest multiples doing the most adjusting.

Ultimately, this week's decline looks to me like a reset more than an opportunity. No chip company's reported demand turned this week, and the one earnings report the sector produced was a record. What changed is the yield on the safest long-term asset in the world. Until that comes back down, a sector that has gained about 66% this year probably shouldn't count on getting June's prices back.

Daniel Sparks and his clients do not have positions in any of the stocks mentioned. The Motley Fool has positions in and recommends Advanced Micro Devices, Micron Technology, and Nvidia. The Motley Fool has a disclosure policy.