Market slides founders overcomplicate

The six-layer model that answers the wrong question

Here is the slide. Title says "Market." Three concentric circles, TAM/SAM/SOM, each with a number under it: $48B, $9B, $740M. Below the circles, a footnote chain explains the math. Total IT spend, times the share that is software, times the share in this category, times the segment the founder can sell to, times an adoption ramp. Every multiplier has a source. Gartner here, a McKinsey report there, a bottoms-up cross-check in the corner. The founder spent a weekend on it and it is, by any standard, a thorough slide.

Then the partner looks at it for four seconds and asks the question the slide does not answer: "Sure, the category is big. But why can this company become huge? Where do you start, and how does starting there get you to that $48B?" And the founder realizes the entire weekend went into proving the prize exists, while the investor was waiting to hear how this particular team reaches it. The number was never in doubt. The path was, and the slide said nothing about it.

That is the tell of an overcomplicated market slide. It is load-bearing on the one thing investors already assume (that some big market exists) and silent on the two things they are deciding (whether you have a real way in, and whether that way in expands). More layers of TAM math make the first problem worse, not better, because each multiplier invites a fight about an assumption nobody at the table cares about.

A market slide has three jobs, not one

Founders treat the market slide as a sizing exercise. Investors read it as an argument about whether this company can get large. Those are different slides. The sizing exercise produces a number. The argument produces a number plus a wedge plus an expansion story. The number alone is the part investors trust least, because every founder can multiply their way to a big TAM, and everyone in the room knows it.

Split the slide into the three things it has to prove, and you can see which job your current slide skips.

Market size is the prize. How big is the thing if you win a meaningful share. This is the part founders over-invest in, because it is the part that feels like homework you can complete. A defensible size estimate takes one or two lines, not a six-layer waterfall.

Market pull is the wedge. The specific first buyer who has this problem so badly they will switch to a new company to solve it. This is the part founders under-invest in, and it is the part that decides the meeting. Pull is not a slice of the TAM. It is a named buyer with a named pain and a reason to move now.

Market path is the expansion. How winning the wedge gives you the right to sell the next thing, to the next buyer, in the next segment. This is what turns a small, believable starting point into a credible case for the big number. Without the path, your wedge looks like a niche. With it, your wedge looks like a beachhead.

A founder with a great size number and no pull or path has a slide that proves the ocean is large and says nothing about their boat. The fix is not a bigger number. It is the two jobs the slide was skipping.

When bottoms-up beats top-down, and when it doesn't

The TAM/SAM/SOM waterfall is a top-down method: start from a huge total and divide down to your slice. It is fast and it is the one investors trust least, because the result is whatever you want it to be. Pick a friendly category definition and a generous adoption rate and any idea becomes a billion-dollar market. Partners have seen a thousand of these, so a clean top-down number reads as table stakes at best and as hand-waving at worst.

Bottoms-up builds the number from units you can defend: number of target customers, times what each one pays you, times realistic penetration. "There are 60,000 US dental practices, our product is $4,800 a year, capture 15 percent over five years and that is roughly $43M of revenue" is a sentence a partner can interrogate and believe, because every term in it is grounded in something real. Bottoms-up is slower and the number is usually smaller, and that smaller number is more persuasive precisely because you cannot fake it.

The rule that decides which to lead with: lead bottoms-up when your wedge is concrete and you can count the buyers, which is almost always true at seed and Series A. Use a top-down number only as the ceiling, the "and this segment is a wedge into a much larger category" line that sits under the bottoms-up math, never above it. The top-down number answers "could this be huge." The bottoms-up number answers "is this real." Investors decide on the second question, so the second number leads.

Bad market claims, and what they actually signal

Most market slides die on one of a handful of moves. Each one signals something to the investor that the founder did not intend to send.

The "1% of a huge market" line is the most common and the most damaging. It sounds humble, but it tells the investor you have no model of how you acquire a single customer, so you are reaching for a share number small enough to feel safe. The fix is the opposite of humility about share: be specific about the first customers and let the share fall out of the bottoms-up math.

The wedge-to-expansion map

Before you touch slide design, fill this in. It forces the two jobs your TAM slide skips and gives you the path story in one structure.

WEDGE-TO-EXPANSION MAP

WEDGE (where you start, must be specific)
  Initial buyer:        [exact role + segment, e.g. "ops lead at
                         50-200 person dental groups"]
  Their pain now:       [the problem they have today, in their words]
  Why they switch now:  [the trigger: a regulation, a cost, a tool
                         that just broke]
  Why you win here:     [why a new company beats the incumbent for
                         THIS buyer specifically]

RING 1 (first expansion, earns the right from the wedge)
  Next buyer/segment:   [adjacent role, segment, or use case]
  Bridge:               [what winning the wedge gives you: data,
                         relationship, workflow, distribution]

RING 2 (the path to the big number)
  Next buyer/segment:   [the broader market the top-down number named]
  Bridge:               [why rings 0 and 1 make this reachable, not
                         just adjacent]

SIZE CHECK
  Bottoms-up (wedge):   [# of wedge buyers x ACV x realistic capture]
  Top-down (ceiling):   [the big category number, as ceiling only]
  Claim:                "We start at [wedge], expand through [ring 1]
                         into [ring 2]. Bottoms-up that path is
                         [$X]; the category ceiling is [$Y]."

The discipline is the bridge lines. If you cannot write a specific bridge from the wedge to ring 1 (a reason that winning the first buyer earns the second), then rings 1 and 2 are not a path, they are a wish list of adjacent markets. A real bridge is concrete: "selling the scheduling tool gives us the practice's no-show data, which is what the billing product needs to underwrite," not "once we have dental we can expand to all of healthcare."

The market slide template

Once the map is filled, the slide writes itself. One screen, three jobs, in order.

MARKET SLIDE (one screen)

[ THE WEDGE ]         <- lead here, not with the big circle
   "We start with [initial buyer] who [pain] and switch because
    [trigger]." One sentence. This is market PULL.

[ THE BOTTOMS-UP NUMBER ]  <- the believable number, built from units
   "[# of wedge buyers] x [$ACV] x [% capture] = $[X] in the wedge."
    Every term countable.

[ THE EXPANSION RINGS ]    <- one simple diagram: wedge -> ring 1 -> ring 2
   Three labeled rings with the buyer at each, and a one-word bridge
   on each arrow (data / workflow / distribution).

[ THE CEILING ]       <- the top-down number, small, as context only
   "This path sits inside a $[Y]B category." One line, sourced.

[ SOURCE NOTES ]      <- where each number comes from, footnote size
   buyer count source, ACV basis, category figure source.

NOT ON THE SLIDE:
- TAM/SAM/SOM as the headline (move the ceiling to one line)
- "we only need 1% of..."
- more than three rings
- any multiplier you cannot defend in one sentence

The order is the whole point. The wedge leads, the bottoms-up number proves it is real, the rings show it gets big, and the category ceiling sits at the bottom as context rather than as the argument. The source notes do the job the six-layer waterfall was trying to do (show you are not making it up) without putting the arithmetic in the investor's face.

Where RoundOS fits

The harder problem is not building one market slide. It is that the framing that lands changes by investor. A vertical-SaaS partner wants the bottoms-up wedge number and gets nervous when you reach for a $48B ceiling. A growth-stage generalist wants to see the category is enormous and treats the wedge as obvious. The same slide that excites one deflates the other, and across thirty conversations you cannot hold in your head which framing worked with whom.

RoundOS pulls those conversations into one place and lets you tag which market framing each investor responded to: the wedge story, the bottoms-up math, the big-category ceiling. After ten meetings you stop guessing. You can see that the operator-led funds light up at the bottoms-up number and the multi-stage funds want the ceiling first, and you walk into each next meeting leading with the version that fits the buyer in the room. The slide stops being one fixed argument and becomes the right argument per investor, because you finally kept the record of what landed.