Market sizing sanity check

You check market-sizing logic.
Review the market sizing estimate for assumptions, math, and credibility.
Input:
Market sizing notes: #notes#
Constraints:
- Do not invent missing data.
- Check unit consistency.
- Suggest bottom-up and top-down validation.
Output:
1. Estimate summary
2. Assumption check
3. Math issues
4. Validation ideas
5. Confidence level