AI and chip stocks lose more than $1 trillion in four sessions, CNBC tally shows

How big, and by whose count

The $1 trillion figure is CNBC's tally for one group of stocks, the top 20 AI and semiconductor companies by value, over four trading sessions. Other outlets measured different groups over different periods. Their figures are not comparable with CNBC's and should not be combined with it:

• A report attributed to Reuters said U.S. chip stocks were "set to lose $2T" since last week. That figure covers U.S. chip stocks only and a longer window that starts last week.
• Benzinga, cited by Herald Business, said six memory and storage companies had lost about $1.09 trillion since 2 October.
• The Philadelphia Semiconductor Index (SOX) fell about 10% over six sessions, Quartz reported, citing Bloomberg.

The biggest losers

According to Herald Business, citing CNBC, losses over the four sessions included:

• Nvidia: down about 5.3%, roughly $291 billion in market value.
• SK Hynix: about $243.8 billion.
• Samsung Electronics: about $237.3 billion.

Herald Business said the three big memory makers, Samsung, SK Hynix and Micron, accounted for about 40% of the total decline.

Thursday's trading

In Asia on Thursday, 15 October, CNBC reported these declines:

| Stock | Thursday change | |---|---| | SK Hynix | down more than 10% | | Samsung Electronics | −8.73% | | SoftBank Group | −7.9% | | Advantest | about −14% | | Tokyo Electron | −6.45% | | TSMC | −1.81% |

In Europe, Infineon fell 5% and ASM International 7%, while ASML was marginally lower.

In the U.S. on Thursday, CNBC reported these moves:

• Down: Nvidia −1.84%, AMD −1.5%, Intel about −2.8%, Dell −6.8%.
• Up: Micron closed up 1.87%.
• AI cloud providers: CoreWeave rose 5.94% and Nebius 1.29% after comments from Nvidia chief executive Jensen Huang.

On Wednesday, 14 October, the day the September consumer price report was released, the Nasdaq Composite fell 1.88% to 26,692.87 and the S&P 500 fell 1.11% to 7,718.94, CNBC reported.

Over six sessions through 14 October, Quartz reported, citing Bloomberg, that Arm fell about 20%, Applied Materials about 15% and Intel about 11%.

Big Tech split

Large technology stocks did not all fall together. In the week through Wednesday's close, according to Money Morning, a market newsletter, Nvidia fell about 6.8% to $221.30, while Apple closed at about $342.96, above $5 trillion in market value. Meta was on track for its best month, up about 10%, the report said.

Why: rates or demand?

Financing and rates. The selloff accelerated after the hot September inflation report revived rate-hike fears. Executives at Broadcom and Intel have said financing is a bigger constraint for AI than chips or power.

Oversupply. A memory-density breakthrough by China's CXMT has stoked fears of a memory glut by 2029, as have comments from Elon Musk about memory supply in 2028. Asian press has described the memory "supercycle" as losing steam.

What's unknown

CNBC has not published the list of stocks behind its $1 trillion tally. The reports reviewed offer two explanations for the selloff, higher financing costs and expected memory oversupply, and do not settle which matters more.