November 5, 2026
Lam Research lost a third of its value on its worst trading day in over three years.
What happened
Lam Research shares fell 13.8 percent, erasing roughly 33 billion dollars of market value. It was the stock's biggest single-day drop in over three years, exceeding every move in that period.
Why it matters
A move this large signals a sudden, severe reassessment of semiconductor equipment demand. The position being unwound is enormous relative to the company's size, suggesting institutional investors are rapidly discounting future growth.
The case against
The selling may be a compressed, one-time repricing tied to broad macro forces like falling oil prices rather than a permanent break in Lam's business. A drop this violent can overshoot fundamentals.
What settles it
Whether demand signals for leading-edge wafers and advanced packaging weaken in upcoming industry reports.