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Build a credible TAM/SAM/SOM with bottom-up and top-down triangulation.
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Based on SOC occupation classification
| name | Market Sizing |
| description | Build a credible TAM/SAM/SOM with bottom-up and top-down triangulation. |
A market size number is only useful if it is defensible. Investors have seen a thousand "100B TAM" slides and discount all of them. This skill builds a number you can defend under questioning by showing your work.
Bottom-up is the credible method; build it before you ever cite a top-down analyst report.
TAM = (number of potential customers) × (annual contract value)
Bottom-up forces you to state your assumptions, which is exactly what a sharp investor will probe.
Cross-check with top-down: take a credible total-spend figure from analyst reports and narrow it by the addressable fraction. If bottom-up and top-down land within ~2x of each other, you have a defensible range. If they diverge wildly, your assumptions are wrong somewhere — find out where.
The number is worthless without the assumptions. Always present:
If you are creating a category, size the adjacent budget you displace and the problem's current cost (including the cost of doing nothing). New-category sizing is about the pain, not an existing line item.
Produce a sizing model with bottom-up TAM, top-down cross-check, SAM and SOM with explicit filters, a low/base/high sensitivity, and a one-paragraph defense of the SOM as the planning number.
Use when a founder needs to understand or model ownership and dilution. Triggers on "model my cap table", "how much will I be diluted", "option pool", "SAFE conversion", "post-money vs pre-money", "what do I own after this round", "pro rata". Turns equity from a black box into a model the founder controls.
Use when a founder needs to prepare materials for investor due diligence. Triggers on "set up a data room", "what goes in a data room", "diligence checklist", "prepare for due diligence", "investors asked for our data room". Builds the organized, staged room that makes diligence fast and confidence-building.
Run structured commercial, financial, technical, and legal diligence.
Help the user build a realistic budget, a debt-payoff plan, and savings goals from their actual numbers.
Use after a term sheet is signed and the founder needs to get to wired money. Triggers on "how do I close the round", "what happens after the term sheet", "confirmatory diligence", "closing documents", "when does the money arrive", "how long to close", "wire the funds". Manages the path from handshake to cash without deals dying in the home stretch.
Use before a founder starts pitching to check they are actually ready. Triggers on "am I ready to raise", "what do I need before fundraising", "will I pass diligence", "fundraise checklist", "what are investors going to find". Surfaces the gaps that kill rounds before the first meeting.
