You have almost certainly seen this slide: three nested circles labelled TAM, SAM and SOM, with a very large number in the outer ring, often sourced from an industry report with a headline figure in the hundreds of billions.
Investors see it in nearly every deck. Most of them skim past it, because it tells them very little about whether your business can become large.
Why the standard slide fails
The numbers are too big to mean anything
“The global healthcare market is worth $10 trillion” is true and useless. Your product addresses a tiny slice of it. Quoting the whole market suggests you have not worked out which slice.
It is top-down
Starting with an industry figure and taking a percentage of it — “if we capture just 1%” — is the most criticised move in fundraising. It assumes the market will hand you share without explaining how.
It is disconnected from the rest of the deck
If your market slide says $50 billion and your projections show $20 million in year five, the gap raises questions rather than answering them.
What investors want to see
The market slide answers one question: can this business become big enough to matter? The most convincing way to answer is bottom-up.
Build it from customers, not reports
Start with the number of potential customers who fit your profile, multiply by what each would realistically pay you per year, and you have a market grounded in your actual business model.
For example: 40,000 mid-sized dental practices in your target countries, multiplied by an average contract of $6,000 a year, gives a $240 million serviceable market. (Illustrative figures — yours should come from real sources.) That number is smaller than a top-down estimate. It is also far more believable, and investors can check the logic in seconds.
Show the path to expansion
If the starting market is modest, show how it grows: adjacent customer segments, new geographies, additional products. This turns a small starting market into a credible, larger opportunity without resorting to inflated numbers.
Explain why now
Markets are more compelling when they are moving. Regulatory changes, technology shifts, changing buyer behaviour or cost curves can all explain why the opportunity is opening today. One well-evidenced tailwind is worth more than a list of five vague ones.
How to design the slide
- Headline the conclusion: “A $240M serviceable market, expanding to $1.1B with adjacent segments” is far stronger than “Market Opportunity”.
- Show the working visually. A simple equation — customers × price = market — laid out in large type is often more persuasive than circles.
- If you use circles, make them honest. Scale them roughly to the numbers and define each layer clearly: who exactly is in the SAM, and why?
- Cite your sources. A small footnote for each figure. It costs nothing and adds credibility.
- Keep it to one or two slides. The market matters, but it should not take over the deck.
Connect it to everything else
The market slide should agree with the rest of the deck. Your customer definition should match the one on your go-to-market slide. Your pricing should match your business model. Your projected revenue should be a plausible share of the market you describe.
When those numbers line up, the market slide stops being a formality and becomes evidence that you understand your business. For a sense of where it fits in the overall flow, see How Many Slides Should an Investor Pitch Deck Be?
Want your market slide to hold up to investor scrutiny? I can help build and visualise the case.