Agent skill · product strategy · yonatangross
market-sizing
TAM, SAM and SOM with top-down and bottom-up estimates and cross-checked assumptions. Use when sizing a market or preparing pitch market slides.
Why this skill is useful
Provides detailed methodologies and formulas for TAM/SAM/SOM market sizing that the AI wouldn't reliably generate on its own.
What it needs
About 3k tokens when loaded. Last updated 2026-08-06. 215 stars on the source repository.
What this skill does
Market Sizing TAM/SAM/SOM framework for estimating addressable market and validating opportunity size. Definitions Metric Definition Question It Answers -------- ------------ --------------------- TAM Total Addressable Market — everyone who could possibly buy "What's the theoretical ceiling?" SAM Serviceable Addressable Market — segment you can actually reach "What can we realistically target?" SOM Serviceable Obtainable Market — realistic share in 3 years "What will we actually capture?" When to Use Top-Down vs. Bottom-Up Method Use When Risk -------- ---------- ------ Top-Down Industry reports exist; investor pitch; quick estimate Overestimates SOM Bottom-Up Sales capacity known; pricing validated; more credible More work; requires assumptions Both (recommended) High-stakes decisions; fundraising; board decks Cross-validate to build confidence Always cross-validate both methods and reconcile within 20%. If they diverge by more than that, revisit your assumptions. Quick Formulas Example: AI Code Review Tool SOM Constraint Model Do not report an unconstrained SOM. Always apply real-world limits: Confidence Levels Confidence Evidence Required ------------ ------------------ HIGH Multiple corroborating sources, data < 2 years old MEDIUM Single authoritative source, 1-2 years old LOW Extrapolated, heavy assumptions, data > 2 years old Always label each number with its confidence level in deliverables. …
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills yonatangross/market-sizing