Key Highlights

● Lam closed at about $230.15 on October 22, among the S&P 500's worst performers.

● Record revenue of $8.22 billion and non-GAAP earnings of $2.20 beat expectations.

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

● Lam guided China sales meaningfully down and flagged supply chain constraints.

Lam Research (NASDAQ:LRCX) tumbled on Thursday, October 22, 2026, closing at about $230.15 and ranking among the worst performers in the S&P 500 after the semiconductor-equipment maker warned that supply constraints will cap its growth.

The selloff rippled across the chip sector. The Philadelphia Semiconductor Index had its biggest one-day drop since June 23, and Lam's warning, together with heavy AI spending plans from Meta Platforms (NASDAQ:META), helped drive the Nasdaq Composite to its steepest fall since June 5.

Record results, cautious outlook

Lam's fiscal first-quarter results, released after the close on Wednesday, were strong. The company reported record revenue of $8.22 billion and non-GAAP earnings of $2.20 a share, beating expectations, along with record margins.

The problem was the outlook. Lam guided December-quarter revenue to $8.6 billion, plus or minus $400 million, and earnings of $2.33 a share, plus or minus $0.15. The revenue midpoint was in line with official consensus but slightly below what buy-side investors had hoped for. Lam also guided China sales, a significant share of its business, "meaningfully down."

Supply chain in focus

Executives said demand was not the issue; supply was. Chief Financial Officer Doug Bettinger 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."

Chief Executive Tim Archer said cleanroom and component constraints will "limit chip makers and equipment companies' ability to fully meet end demand" into 2027. He also sought to distinguish the current situation from past supply disruptions: "this is nothing like that… I think we'll be caught up very shortly."

Analysts trimmed their targets. Needham cut its price target to $290 from $390, and Morgan Stanley lowered its target to $339.

A rout across chips

Lam's warning hit chip stocks broadly. KLA (NASDAQ:KLAC) sank, Applied Materials (NASDAQ:AMAT) fell to close at $375.58, and ASML (NASDAQ:ASML) closed at $1,560.54. Teradyne (NASDAQ:TER) plunged, and Intel (NASDAQ:INTC), AMD (NASDAQ:AMD), SanDisk (NASDAQ:SNDK) and Marvell (NASDAQ:MRVL) all fell sharply. Nvidia (NASDAQ:NVDA) closed at $212.21 and was one of the biggest drags on the S&P 500, according to market reports.

The report from Meta Platforms, which showed heavy capital spending and negative free cash flow, compounded the pressure, as did comments from Nvidia's chief executive. He said, "The demand of the capital is much greater than the availability of the capital."

The S&P 500 fell 93.74 points to 7,663.43, its worst day since July, and the Nasdaq Composite dropped 694 points to 26,008.86. The Nasdaq lost about $1 trillion in market value.

Away from chips, the market was healthier. About two of every three S&P 500 stocks rose, according to market reports, and consumer staples and health care hit records.

Lam's Supply Constraints Meet Investor Patience

Investors will watch for signs of whether Lam's supply constraints ease as quickly as Archer suggested, or whether they persist into 2027 as the company has flagged. Updates from chip makers and other equipment suppliers will be scrutinized for similar bottlenecks. Teradyne reports on October 27 and Intel on October 29, offering fresh reads on the sector, while big-tech capital spending plans from Microsoft (NASDAQ:MSFT), Alphabet (NASDAQ:GOOGL) and Amazon (NASDAQ:AMZN) next week will show whether demand for chipmaking tools stays strong.