Research
Notes on thesis discipline and portfolio coherence.
Short essays on how serious investors track reasoning, define invalidation, and surface contradictions across a book.
Jun 13, 2026 · 6 min read
The disposition effect: why investors sell winners and ride losers
Investors systematically realize gains too early and hold losses too long. The effect is one of the most replicated findings in behavioral finance, and it has a structural fix.
Read →Jun 13, 2026 · 5 min read
The pre-mortem: how prospective hindsight improves investment decisions
A 1989 experiment showed that asking people to imagine an outcome has already happened produces dramatically more specific reasoning about why it happened. The technique transfers directly to investment theses.
Read →Jun 13, 2026 · 6 min read
Overconfidence and trading frequency: the cost of conviction
Two decades of brokerage-account research show that the investors who trade the most underperform the investors who trade the least, and the gap is explained by overconfidence rather than information.
Read →Jun 13, 2026 · 6 min read
Base rate neglect in stock picking
Investors evaluate individual companies on their specific story and systematically ignore the base rate of what happens to companies in that category. The bias has been documented since 1973 and remains the dominant source of single-name forecasting error.
Read →Jun 13, 2026 · 4 min read
How to write a falsifiable investment thesis
Most theses are built to survive any outcome. A falsifiable thesis is built to fail under specific, pre-defined conditions — and that is what makes it useful.
Read →Jun 11, 2026 · 6 min read
Why most investors can't explain why they were wrong
Investors lose money not because they were wrong, but because their original reasoning was never written down precisely enough to be tested against reality.
Read →Jun 11, 2026 · 5 min read
What is an investment thesis invalidation condition?
An invalidation condition is a pre-committed, observable trigger that tells you your thesis is wrong — not your position is losing money, but your reasoning has failed.
Read →Jun 11, 2026 · 7 min read
How cross-position contradictions destroy portfolio returns
Most portfolios contain two or three theses that quietly contradict each other on the same underlying variable. The contradictions are invisible position-by-position, but they cap your upside and double your downside.
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