A thesis is the single most useful thing a value investor writes. It is the argument for owning a business: why it is worth more than the price, what edge keeps it that way, and the short list of things that would prove you wrong. You write it once, then grade it against reality as new filings arrive. The discipline is not the prose, it is being specific enough to be caught out.
The blank page is what stops most people. So here is a complete thesis for one company, Costco, broken into the parts the app asks you for. It is an illustration of the shape, not investment advice; the numbers are rounded and will be stale by the time you read this. Copy the structure, not the conclusion.
The claim, in one line
Start with the sentence you would defend to a skeptic:
Costco is a membership business wearing a retailer's clothes, and the market prices the retailer.
That is the whole thesis compressed. Everything below either supports it or is a reason it might be false. If you cannot write this line, you do not have a thesis yet, you have a watchlist entry.
Why it might be mispriced (the variant view)
A thesis only earns its keep when you can say why the price is wrong. "It is a great company" is not enough; great companies are usually priced as great companies. You need a variant perception, a way your view differs from the consensus baked into the price.
For Costco: the market values it on store-level grocery economics, where margins are thin and competition is brutal. But the real engine is the annual membership fee, which renews above 90% and carries almost no incremental cost, so it makes up roughly two-thirds of operating income. That fee stream behaves like a subscription annuity, not a grocery margin. The claim is that the multiple under-weights the durability and quality of that annuity.
The moat: why it lasts
The variant view only holds if the advantage is durable. Here you write down the edge and the marks it leaves in the numbers (the moat scorecard checks these for you).
Costco's edge is scale used as a weapon: it runs on the thinnest product markup in retail and hands the savings to members, which competitors with shareholders to feed cannot match. The marks: a high and steady return on capital, low debt, and a membership renewal rate that barely moves through recessions. The renewal rate is the single number that proves the moat is real, so it belongs in your vitals.
What it's worth
Value is always relative: to the business's own history, to peers, and to the alternative of owning bonds. You do not need a precise number, you need a range and a margin of safety. A discounted cash flow on mid-single-digit growth, or a simple "what multiple does this annuity deserve," both land at a fair value, and the gap between that and the price is your margin of safety.
The honest entry here often reads: "fair value roughly X, the stock is inside the band but no longer cheap." Writing that down is what stops you from buying a wonderful business at a foolish price.
What would make me wrong
This is the section amateurs skip and professionals lead with. List the specific, falsifiable things that would break the thesis, not vague worries:
- Membership growth stalls in saturated markets, so the annuity stops compounding.
- Gross margin falls structurally (pricing, not mix), signalling the cost edge is eroding.
- Renewal rate drops below the floor you set, the clearest sign the moat is leaking.
Each of these should map to a number you can watch. A risk you cannot measure is just anxiety.
The verdict
Close with what you will actually do: own a position, add only on a pullback that restores the margin of safety, and re-underwrite if a vital breaks. The verdict is a plan, not a rating.
The vitals: the numbers that must stay true
A thesis is not static prose, it is a claim you monitor. Pick a handful of metrics that have to hold for the argument to survive, and a rule for each. For Costco:
- Membership renewal ≥ 90%
- Gross margin ≥ its recent floor
- Return on invested capital > 15%
- Net debt / EBITDA ≤ 1.5×
In the app you pin these straight from the analysis page, and they are snapshotted the day you write them. When a new filing lands, you see whether the number still clears your rule, or whether reality has started to disagree with your thesis.
Conviction and the journal
Last, record how sure you are (a conviction from 1 to 10) and keep a dated journal of what changes your mind. The journal is the antidote to hindsight: it shows what you actually believed and when, so you can grade your own decisions later. When a quarter beats and you raise conviction, write the line. When a vital breaks and you start doubting, write that too. The record of a changing mind is worth more than any single verdict.
That is the whole shape: a claim, a variant view, the moat, a value range, the risks, a plan, the vitals, and a journal. Open any ticker, start a thesis, and fill in the parts you can. You do not need all of it on day one; you need the claim and one or two vitals, and the rest grows as you learn the business.