Letters — AEA Capital Research

Post-Mortems Logged 1 Original Thesis · Reality · Lesson, published in full

Policy Rules Currently In Breach 0 Zero technical breaches — but the single-position cap was satisfied by a price pullback, not the trim that was owed; full context on the Compliance Ledger

Quarterly Briefing

The AEA Strategy Briefing

Macro positioning, the semiconductor/AI-infrastructure thesis, and current portfolio reallocation, assembled onto one page from data already published across this site.

↓ View the Q3 Strategy Briefing HTML briefing — use your browser's Print → Save as PDF to export

Looking for what I got wrong?

Every full letter includes a dedicated "Portfolio Review & Retrospective" section, using the same repeatable structure every time so mistakes are checkable rather than buried in prose:

The Original Thesis: What I said I believed or intended to do, quoted from a prior letter.
The Reality: What actually happened, including whether the outcome came from my own action or from the market resolving something I didn't.
The Lesson: The specific process or risk-assessment flaw exposed — not a restatement of the mistake, but what changes going forward because of it.

Jump straight to the latest post-mortem.

How this archive is organized

Two kinds of entries live here, both dated and both public even when they're not flattering:

Monthly Positioning: The full letter — thesis, performance vs. SPY, and the Portfolio Review & Retrospective section above.
Interim Notes: Shorter, published when something material happens between full letters — a real event that moved a position enough to be worth writing down in real time.

8 letters published since the 2022 Founding Note — see the About page for the full practice this archive is part of.

Interim Note July 31, 2026
Alphabet Jumps 6.7%, Micron and SanDisk Slide Again — No Trades
Amazon and Apple were the day's two biggest movers, and I hold neither. Alphabet jumped 6.73% on its own earnings, Micron and SanDisk gave back ground to rising rates, Vertiv and Fortinet rallied. No trades.
Interim Note July 28, 2026
SanDisk Falls 14%, NBIL Falls Nearly 20% — A Rough Tuesday, No Trades
A Chinese chipmaker's $487 billion IPO hit the memory/AI-infrastructure bucket hard — SanDisk, Micron, Nebius, NBIL, CoreWeave, Arm, and more all down — while ServiceNow and Netflix rallied. No trades.
Interim Note July 24, 2026
A Second Rough Day for AI Infrastructure, and an Earnings Beat the Market Sold Anyway
Five positions moved sharply on two separate storylines Friday — neocloud capex skepticism hit CoreWeave and Nebius, memory-cycle doubt hit SanDisk, Micron, and Arm — while Intel fell despite its best quarter in 15 years. No trades.
Interim Note July 23, 2026
American Airlines' Roughest Day in Months, and Alphabet Falls Despite Beating Estimates
An oil-price shock and an AI-capex re-rating hit on the same Thursday, landing on two positions I hold for very different reasons — and one, Micron, actually benefited.
Interim Note July 22, 2026
ServiceNow's Roughest Day in Months, and SpaceX Falls Further Below Cost
A quiet index day hid a genuinely mixed one for the book — ServiceNow's worst day in months and a fourth SpaceX decline in two weeks, partly offset by gains in the power and AI-hardware names.
Interim Note July 21, 2026
Nvidia Just Told the Market What It Thinks of Nebius — And SanDisk Finally Stopped Falling
Nvidia's disclosed stake in Nebius and a bullish Morgan Stanley call on SanDisk both hit the same day for two of my own positions — worth writing down while it's happening.
Interim Note July 20, 2026
SpaceX Drops Below My Cost Basis, and I'm Still Not Selling
A quiet index day hid two sharp moves in my own Spec bucket — SpaceX on a scrubbed Starship test, Tempus AI on acquisition scrutiny — and why neither one is a trade.
Interim Note July 19, 2026
I Went and Checked the AI Capex Number
A follow-up to the July 17 note: real Q1 2026 SEC filing data on Alphabet and Meta's free cash flow coverage of their own AI capex, and what it does and doesn't change about holding both.
Interim Note July 17, 2026
A Rough Session, and Why I'm Not Touching Anything
A broad Thursday selloff hit Netflix, SanDisk, and SpaceX on three unrelated theses, against a backdrop of rising worry about whether AI infrastructure spending still pays for itself.
Interim Note July 10, 2026
A Good Week for the Book, for Two Unrelated Reasons
Micron's $250B manufacturing commitment and Meta's confirmed AI chip start date both moved the book green this week — on two theses that need to stay separate in my head, not one.
Interim Note July 8, 2026
One Theme, Three Different Reactions
Alphabet joins the Dow, Meta's own stock whipsaws on its cloud pivot, and the same AI-infrastructure theme moves four holdings four different ways in one week.
Interim Note July 7, 2026
A Record Market, a Rough Week for the Core Sleeve
A short between-letters check-in: a record Dow, a real selloff in 28.52% of the book, and why that combination is worth writing down.
Monthly Positioning July 2026
Portfolio Composition & Ongoing Risks
An honest map of all 32 holdings and the three things that could hurt me most.
Interim Note June 19, 2026
The Turnaround Position Just Had Its Best Week
Intel's Apple foundry deal confirmation moved a position bought years before the deal existed — a short note on what that does and doesn't prove.
Founding Note 2022 · written in retrospect
Why I Wrote the Rules Before I Needed Them
How the $500 start and the Investment Policy Statement actually came first — and an honest note on the limits of reconstructing that period from memory.