How to Write an Investment Memo (With a Template)

An investment memo is the written document an analyst prepares to argue for a position, so that an investment committee can weigh the argument, the evidence, and the risks before capital is committed. A good one contains a clear thesis, an honest account of the business and its economics, a valuation with scenarios, a stated variant perception explaining why the market may be wrong, and a list of the specific things that would prove the thesis wrong.

That last part is what separates a memo from a brochure. A brochure lists reasons to be excited. A memo makes a claim that can be checked and later graded as right or wrong. This guide walks through the craft of the memo and gives you a reusable template to adapt. It teaches structure only. Nothing here is a recommendation on any security, and any example is generic and illustrative.

What a memo is actually for

A memo has two audiences and two jobs. In the moment, it exists to persuade a committee that a position deserves capital and a slot in the book. Months later, it exists to be re-read, so the desk can ask a simple question: did the thing we said would happen actually happen?

Both jobs push in the same direction. They reward a memo that commits to a falsifiable claim and against one that hedges everything. If you cannot state, in one sentence, what you believe and why the market disagrees, you do not yet have a memo. You have notes.

Write for a skeptical reader who is short on time and has seen many pitches. Assume they will attack the weakest link first. Your job is to find that weak link before they do and address it in the open.

The template

Use this as a skeleton, not a straitjacket. Cut sections that do not earn their place and expand the one or two that carry the argument. The order matters: the summary and thesis come first because a busy reader should be able to stop after the first page and still know what you think.

Section	What it answers	Keep it to
1. Summary and thesis	What do you believe, and in one line, why?	A paragraph
2. Business overview	What does the company do and how does it make money?	Half a page
3. Industry and competitive position	What is the structure of the market and where does the company sit?	Half a page
4. Financial analysis and key drivers	What do the numbers say, and which few variables actually drive the outcome?	The core
5. Valuation and scenarios	What is it worth under bull, base, and bear cases?	A page
6. Variant perception	Why might the market be wrong right now?	A tight paragraph
7. Key risks and what breaks the thesis	What would make you sell, and what are you assuming that could be false?	Half a page
8. Position sizing and monitoring	How much, and what will you watch to know if you are right?	A short section

Here is what each section is really asking for.

Summary and thesis. Lead with the conclusion. A single sentence should state the position and the core reason. Follow it with three or four bullets: the setup, the expected outcome, the time horizon, and the one thing that has to be true. A reader who stops here should be able to repeat your argument back to you.

Business overview. Describe the company as an operating machine, not as a ticker. What does it sell, to whom, and how does revenue convert into cash? Keep it short. The goal is shared context, not a history lesson.

Industry and competitive position. Zoom out to the market. Is it growing or mature, concentrated or fragmented, cyclical or steady? Then place the company inside it. What is the source of any advantage, and is that advantage durable or borrowed? A memo that treats the company in isolation misses where returns usually come from.

Financial analysis and key drivers. This is the core, and it is where most weak memos drown. The trap is a wall of facts: every ratio, every segment, every footnote, with no hierarchy. Resist it. Identify the two or three variables that actually determine the outcome, whether that is unit volume, gross margin, a single input cost, or the reinvestment rate, and build the section around them. Show the history, then show what you expect and why. Everything that does not move the answer belongs in an appendix.

Valuation and scenarios. State what you think it is worth and how you got there. Then stress it. A single point estimate hides the range of outcomes; a bull, base, and bear case reveals it. The useful question is not “what is my target” but “what does the current price imply, and is that set of expectations too low, about right, or too high?”

Variant perception. This is the heart of the memo and the section most often missing. It answers a blunt question: if this is such a good idea, why is it available at this price? A real variant perception names the consensus view and says precisely how yours differs. Maybe the market is over-extrapolating one bad quarter. Maybe it is anchored to a segment that no longer matters. Maybe a structural change has not yet shown up in reported numbers. If your view is the same as everyone else’s, you have no edge, and the memo should admit it.

Key risks and what breaks the thesis. List the honest risks, ranked, not a boilerplate paragraph. For each, say roughly how likely and how damaging it is. Then go further: name the specific developments that would prove you wrong. A concrete “if margins fall below the prior trough for two straight quarters, the thesis is broken” is worth more than a page of generic caution. This is the section that earns a reader’s trust, because it shows you have argued against yourself.

Position sizing and monitoring. Conviction and evidence should map to size; a thesis with wide scenarios and thin data does not deserve a large weight. Close with the monitoring triggers: the handful of data points, filings, or events you will track to confirm or kill the thesis. This is what turns a memo from a one-time pitch into a living document.

Strong versus weak, section by section

The difference between a strong memo and a weak one is rarely the amount of work behind it. It is whether that work is organized into an argument.

A weak memo describes a company. A strong memo makes a claim, states why the market disagrees, and names what would prove it wrong.

A few contrasts that show up again and again:

• Facts versus argument. The weak memo presents everything it found. The strong memo presents only what supports or tests the thesis and cuts the rest.
• Optimism versus falsifiability. The weak memo lists reasons to be hopeful. The strong memo states a claim precise enough to be graded later.
• Consensus versus variance. The weak memo repeats what the market already believes. The strong memo isolates exactly where it departs from that belief.
• Boilerplate versus honest risk. The weak memo buries risk in a disclaimer. The strong memo ranks the real risks and names the break points.

Working the process

Writing forces thinking. Many analysts find the thesis only after drafting the financial section and realizing the numbers say something they did not expect. Let that happen. If the memo talks you out of the position, it did its job.

A practical sequence: gather and reconcile the data first, then draft the driver analysis, then write the variant perception, and only then write the one-line thesis at the top. The summary is easiest to write last, once you know what you actually believe. Tools that keep the point-in-time record straight, including research terminals like the one we build at Altys, help here mainly by reducing the time spent assembling facts, so more of it goes to the argument. But no tool writes the thesis for you.

Keep the main document tight and push detail into appendices. A committee reads the argument; it consults the model. If a reader has to wade through exhibits to find your claim, the structure has failed.

What separates a strong memo

A strong memo is not the one with the most exhibits. It is the one built around a single falsifiable claim, honest about its risks, and clear about why the market may be wrong. If a reader can restate your thesis, name the two drivers that matter, and tell you what would make you sell, the memo has done its work. Everything else is supporting material. Write the claim first, argue against it hardest, and let the structure carry the rest.