Kioxia makes memory chips in Japan. Its latest quarterly profit came in short of what analysts expected. On Monday, Nov. 2, the stock fell 16%. One report, one day, about a sixth of the company's value gone. The Journal's Stock Spotlight box on Tuesday listed it with the day's biggest movers.
Memory has been one of the hottest parts of the AI trade this year. The chips that store data have been in short supply, and their prices have run up. That's why a memory maker's miss gets attention. Kioxia is a peer of Micron (MU) and SanDisk (SNDK). Micron closed Monday at $833.59, down $51.15, by the Journal's stock table. SanDisk closed at $1,075.08, down $75.81. One supplier's miss doesn't tell you the memory market turned. It tells you the market is listening for bad news now, and it didn't used to.
Alstom builds trains in France. On Monday it cut its guidance. It blamed technical and production problems with some of its products. The stock plunged 26%. That's about a quarter of a company gone on one update, in a business about as far from AI chips as you can get. Bad surprises aren't a tech thing. They're a single-stock thing.
The rest of Monday's board
Intel (INTC) had its worst day ever on Friday, Oct. 30. On Monday it fell another 8.8%. Nvidia (NVDA) opened the week higher and closed down 1.3%. SpaceX gained 1.2%. Marriott rose 4.3% on strong hotel demand in the U.S. and Canada. Estée Lauder raised its outlook, reported sales up 6.7%, and still dropped 4.1%. Apple and Palantir slipped ahead of their own reports after the close. Good news didn't always buy a green day. Bad news got punished fast.
Our read
This is an Investments/Risk · IN04 story. Micron is held at weight in 23 of our model books, and it's part of the North Star slice. SanDisk is in one book. Kioxia and Alstom aren't held. We didn't add or trim anything on Monday. One supplier's miss is a signal to watch, not a verdict on the group. We'd want to see Micron's own numbers before we changed our view on memory. A miss at one company can mean a problem at that company, and nothing more.
Here's your check this week. Open your 401(k) or brokerage app and find your biggest single stock. Ask what a 16% day, or a 26% day, would do to your plan. If the answer scares you, the position is too big, however good the company is. A position limit is the umbrella here. You pick it on a sunny day, and you don't argue with it once it's raining. If you're not sure where to set yours, that's a short conversation we have often.