Building an Investment Thesis
How to turn research into a short written argument for an investment, including the measures to watch and, most important, the specific evidence that would prove it wrong.
The short version
An investment thesis is a short written case: what the business is, why it's good, what the price assumes, which measures to track, and what would prove you wrong. The last part matters most. Specific, observable thesis breakers, decided in advance, keep you from explaining away bad news later. A premortem helps find them: imagine the investment has already failed and list the likely reasons. Writing it down makes your reasoning testable, and gives you something to check against as results come in.
By the end of this lesson, you'll be able to
- Write an investment thesis with its main parts
- Define specific, observable thesis breakers
- Use a premortem to find risks you might otherwise miss
Why this matters
Research produces a lot of notes. A thesis turns them into a decision you can explain in a few sentences, and test later. Without one, it's easy to forget why you bought something, and to invent new reasons whenever the old ones stop working. With one, you know what you expected and can see whether it's happening.
The parts of a thesis
- The business in one sentence. If you can't summarize how it makes money, you're not ready.
- Why it's a good business, with the evidence from your research.
- What the price assumes. A great business can be a poor investment at the wrong price. The valuation module of this part covers how to judge this.
- What to track: the few measures that show whether the story is playing out.
- What would prove you wrong: specific, observable evidence, decided now.
- When to review it, such as after each annual report.
The rest of this lesson is for members
Still to come in this lesson: Thesis breakers, the key takeaways, and 2 quiz questions with explanations.
Membership opens every lesson in the curriculum, the capstone projects, the interactive tools, and the members-only channels in the Hyperion Entities Discord. The first lesson of every module stays free.
Go deeper
- Writing the Thesis coming soonResearch Workshop (depth track)
- Monitoring Positions and Revisiting a ThesisPart 5: Building a Portfolio
- Keeping a Research Journal coming soonResearch Workshop (depth track)
Notes and sources
- Harvard Business Review. Gary Klein, Performing a Project Premortem (September 2007). Checked 2026-10-01.