Key Highlights

● AMD traded around $509.79 on the morning of October 22, well below the prior close.

● Lam guided December-quarter revenue to $8.6 billion, plus or minus $400 million.

● The Nasdaq-100 lost about $1.32 trillion in market value.

● Forty-nine of the Nasdaq-100's 100 members still rose.

Advanced Micro Devices (NASDAQ:AMD) tumbled on Thursday, October 22, 2026, ranking among the heaviest decliners on the Nasdaq-100 as a selloff swept through the semiconductor industry.

The chip designer was trading around $509.79 in the morning already well below the prior day's close. Market data listed AMD alongside Intel (NASDAQ:INTC), SanDisk (NASDAQ:SNDK) and Marvell (NASDAQ:MRVL) as chip stocks that suffered especially steep drops. There was no company-specific news; the move came from a sector-wide selloff sparked by Lam Research (NASDAQ:LRCX)'s supply warning, according to market data.

Lam's warning rippled out

Lam Research, which makes equipment used to manufacture chips, reported record revenue of $8.22 billion and adjusted earnings of $2.20 a share late Wednesday. But its December-quarter guidance of $8.6 billion, plus or minus $400 million, came with a warning about supply constraints, and the midpoint was slightly below what some investors had hoped for.

Lam's chief financial officer said revenue would have been higher without "near-term supply chain constraints that we are actively managing," and added that "things are going to continue to be constrained." Lam's chief executive said clean-room and component shortages will "limit chip makers and equipment companies' ability to fully meet end demand" into 2027.

For investors, that raised a worrying possibility: even if demand for AI chips stays strong, the industry may not be able to produce and ship as much as expected, as quickly as expected.

Meta and Nvidia added fuel

The supply warning landed alongside worries about the financing of AI. Meta Platforms (NASDAQ:META) narrowed its 2026 capital-spending range to $135 billion to $145 billion and swung to negative free cash flow of $2.12 billion, its first cash outflow in more than a decade, according to market data. Nvidia (NASDAQ:NVDA)'s chief executive said that "the demand of the capital is much greater than the availability of the capital."

AMD sells data-center processors and AI accelerators that compete with Nvidia's chips, so it is closely tied to the same spending decisions by cloud giants and AI developers.

A heavy day for the Nasdaq-100

The Philadelphia Semiconductor Index suffered its biggest one-day drop since June 23. The Nasdaq-100 lost about $1.32 trillion in market value, and an analysis found that AI and chip names accounted for the overwhelming bulk of the decline. Even so, 49 of the index's 100 members rose.

The broader Nasdaq Composite fell 694.00 points to 26,008.86, its steepest drop since June 5, ending a seven-session winning streak. The S&P 500 fell 93.74 points to 7,663.43, its worst day since July.

AMD Looks to Hyperscaler Spending Plans

The next big test for AI chip demand comes next week, when Microsoft (NASDAQ:MSFT) and Alphabet (NASDAQ:GOOGL) report on October 28 and Amazon (NASDAQ:AMZN) on October 29. Their capital-spending plans will directly affect orders for AI processors from AMD and its rivals. Investors will also look for any update from AMD on its own supply situation in light of Lam's warning, and for the Federal Reserve's decision on October 28.