From the portfolio — October 18, 2026

The Memory Thesis Needs a Competition Page, Not Just a Demand Chart

A retrospective letter on SNDK, MU and what the week’s semiconductor concerns mean for the questions this book should ask.

Micron chief executive Sanjay Mehrotra at a meeting with Taiwan’s president
Micron chief executive Sanjay Mehrotra at a meeting with Taiwan’s president. The portfolio letter considers the company’s competitive position. Archive photo: Taiwan Presidential Office / Wikimedia Commons · CC BY 4.0.

The week’s concern about Chinese memory competition belongs in the research even if the commercial consequences are still uncertain. A threat does not have to be fully realized before it matters to a valuation. It does have to be examined before it becomes a conclusion.

SNDK and MU are both in the published portfolio, but they are not interchangeable memory exposures. Product categories, customers, competitive positions and the investment needed to expand capacity differ. I should not use a generic “memory demand is strong” sentence to answer a specific question about either one.

The earlier Sandisk cap issue also remains part of the record. I cannot infer from subsequent prices whether it was corrected, and I should not quietly treat a research concern as proof that a trade was required or completed. Sizing, thesis quality and transaction history need their own evidence.

I would add a competition review that distinguishes technical capability, customer qualification, commercial yields and available volume. Then I would test margins under a less favorable pricing environment. If the valuation only works when exceptional margins last indefinitely, that is the assumption to challenge.

This is a retrospective portfolio reflection, not a reconstructed diary. It makes no claim about trades during the week and does not report a broker-verified return. What it can do is keep the demand story from crowding out the harder question: how much of the industry’s growth will remain available to the shareholders of the companies I actually own?

Aydin Ali
AEA Capital Research

Reporting notes

  1. Reuters · October 13 Trading Day
  2. Reuters · CXMT competition and AI concerns
Dates, image credits and methodology

This page covers October 18, 2026. First published October 27, 2026 as retrospective coverage; revised October 29, 2026. The coverage date is not a claim of contemporaneous publication.

Photos depict identified subjects and are credited individually. Archival images are not presented as photographs of the reported events. No interviews, transactions, eyewitness details or price series have been invented.

Educational personal research, not investment advice. Disclosures.