Market Sizing and Feasibility in Singapore. How to Build a Business Case an Investor Will Back.
I have watched investors stop listening at the same moment, more than once. A founder puts up a slide. It says the market is worth two billion dollars. The number is large, round, and unsourced (it is always unsourced), and the room quietly decides the founder has not done the work. The pitch is not dead, exactly. It now has to climb back from a position of doubt, and all because the most impressive slide was the least believable one.
That is the strange thing about market sizing. Founders reach for the biggest number they can defend, thinking size is what persuades. What persuades a reader is the working underneath it. A board or an investor reading a business case is not asking whether the market is big. They are asking whether this team understands the market well enough to take a piece of it. A clean two-billion-dollar headline answers neither question, and a smaller number with visible reasoning answers both.
So this guide treats market sizing as what it actually is, an argument you build rather than a number you find. Get the argument right and feasibility, the harder question of whether you can win and operate, has somewhere solid to stand.
Why a big number is not a business case
Singapore makes the trap easy to fall into. With a total population of 6.11 million and an unusual amount of open public data, anyone can assemble a top-down market figure in an afternoon (I have done it in an afternoon, which is exactly the problem). Take a category total, apply a percentage, present the result. It looks rigorous. Actually, that is unfair to rigour. It looks like rigour, which is a different and more dangerous thing, because every step inherited an assumption from somewhere else, and nobody in the chain checked whether those assumptions describe your business.
A market size only becomes a business case when it answers a narrower question. Not how big is the category, but how much of it could realistically end up as your revenue, by when, against who. That shift, from the category to your slice of it, is the whole job. It is also where most business cases quietly fall apart, because the founder sized the category and then assumed the slice. The assumption usually arrives as a single confident percentage, and a single confident percentage is the thing experienced readers distrust most.
The three layers of a market size
Any honest market size has three layers, and the work is keeping them apart. Founders get into trouble by quoting the top layer and behaving as though it were the bottom one. I think of them as the whole market, the reachable market, and the winnable market, though the labels matter less than the discipline of never letting one stand in for another.
Everyone who buys the category at all.
The headline total. Built top-down from public data on population, spending, and category value.
Quoting this as if it were available to you. It is the category, not the opportunity.
The slice your model can actually serve.
The whole market filtered by your real constraints, price band, location, channel, and target segment.
Skipping the filter, so the case never narrows from the category to the business.
The slice you can realistically take, and by when.
Built bottom-up from your capacity and a defensible share, against the competitors already there.
Assuming a flat percentage of layer one instead of building this from the ground.
Whole, reachable, winnable. A business case lives in the third layer. The first two exist to get you there honestly.
The whole market is context, not opportunity
The top layer is the easiest to build and the easiest to misuse. It tells a reader the category is large enough to be worth a conversation, and that is its entire job. Household expenditure data and category statistics give you a credible total, and a credible total is genuinely useful as a ceiling. The error is treating the ceiling as the room. A category worth a billion dollars where four entrenched players hold ninety percent of it (and intend to keep it) is, for a newcomer, a far smaller market than the headline admits.
The reachable market is where honesty starts
Layer two is the filter most business cases skip, and skipping it is the single most common reason a case reads as naive. Your business does not serve everyone. It serves a price band, a set of locations, a channel, a segment with a particular need. Each of those is a real cut, and applying them shrinks the number, sometimes dramatically (a headline total can lose two-thirds of its size by this layer). That shrinking is not bad news. It is the case becoming believable. A reader who watches you narrow the whole market down to a reachable one, with stated reasons at each step, trusts the rest of the document more.
The winnable market is the one you defend
The bottom layer is the number the business case actually rests on, and it cannot be reached by multiplying. Your winnable market is set by what you can physically deliver, how fast you can build awareness, and how much share is loose enough to take from competitors who will not stand still. This is where consumer research earns its place, because winnable share depends on whether real people would switch to you, and stated intent is a poor guide to that. We have written about the gap between what consumers say and do, and a winnable-market figure built on survey enthusiasm rather than behaviour is the figure that disappoints a board a year later.
Top-down and bottom-up, and why you need both
There are two ways to size a market (more than two, but two that matter), and a case that uses only one has a blind spot. Top-down starts from a published total and narrows. Bottom-up starts from your own units and builds. Each is good at catching the other's mistakes, which is the real reason to run both.
| Approach | How it works | Strength | Watch out for |
|---|---|---|---|
| Top-down | Start from a published category total, narrow by segment, geography, and price band | Fast, and anchored to authoritative public data | Quietly inherits other people's assumptions, and tends to flatter |
| Bottom-up | Build from your own capacity, price, outlets, and a realistic reach per period | Grounded in the business you are actually proposing | Slow, and only as sound as the inputs you put in |
| Triangulation | Run both, then trust the case only in the range where the two roughly agree | Exposes the assumption that one method alone would hide | Needs the discipline to investigate the gap, not split the difference |
When the two methods land far apart, that gap (uncomfortable as it is to present) is the most useful thing the exercise produced. It means an assumption somewhere is wrong, and finding which one is worth more than the tidy average a tired analyst would reach for instead. A business case that shows both numbers and explains the gap is far more persuasive than one that shows a single figure with no seams.
Where feasibility goes past the number
Market sizing tells you the prize. Feasibility asks whether you can actually collect it, and it covers ground a number never will. A feasibility study pairs the winnable market with three harder checks (none of which a spreadsheet can settle alone). Whether consumers will genuinely choose you, which is a behavioural question for focus groups and in-depth interviews, not a spreadsheet. Whether the economics hold at the price the market will accept. And whether the operating context, the regulation, the costs, the talent, the cultural fit of the offer, will let the plan run as drawn.
That multi-angle read is what our research expertise is built around, and it is why feasibility and the broader entry decision belong together. Sizing is one input. The market entry guide sets out the full sequence, and for sectors where the business case carries real regulatory weight, such as financial services, the feasibility work has to be heavier still. A number on its own has never funded anything. A number with a feasibility argument around it is what a board signs.
What an investor or a board actually reads
Here is what experienced readers look for, and most of it is not the headline. They read for the working (the build, not the headline). They want to see the chain from the whole market down to the winnable one, with a stated reason at every narrowing. They look for the assumptions pulled out and named, so they can argue with them, because an assumption you can see is one you can trust. And they look for a sensitivity range, what the case looks like if the key assumptions come in worse than hoped, since a business case with only one outcome is not a case, it is a wish.
The founders who raise well, in our experience, are not the ones with the biggest number. They are the ones who can be questioned on any line of the build and have an answer. That is what a good market sizing and feasibility study buys you. Not a slide. The ability to defend the slide, which is the thing the room is actually testing. If you are unsure how deep your study needs to go, our guide to research pricing and our go-to guide for research in Singapore both help you scope it.
Size before you spend, not after
The sequencing argument from the rest of this cluster holds here too. A market sizing and feasibility study is the cheapest serious thing you can do, and it belongs near the front of the process, before the lease, the hires, and the inventory. Run it early and a weak case costs you a study. Run it late and a weak case costs you the year you spent acting on a number nobody had pressure-tested. A clear research brief is what keeps the study aimed at the decision you actually face.
Before the next version of your business case, find the single percentage doing the most work. The share you assume you will take, the conversion you expect, the growth you have penned in. If that one number is a guess wearing a decimal point, the case is built on it, and so is everyone's money.
What to settle before you size a market in Singapore
What is the difference between market sizing and a feasibility study?
What is the difference between top-down and bottom-up market sizing?
Why do investors distrust a large market-size number?
How much of the market can a new entrant realistically win?
When should I commission market sizing and feasibility research?
A market size is an argument, and like any argument it is judged on its reasoning, not its volume. Build it in three honest layers, run it both ways and study the gap, wrap it in a feasibility check that asks whether you can actually win and operate, and you end up with something a board can sign without holding its breath. The headline number will be smaller than the one you first wanted to put on the slide. It will also survive the questions, and surviving the questions is the entire point.
Building a business case that survives the questions
A market size persuades a board through its working, not its size. If you need a sizing and feasibility study built in honest layers, with the assumptions named and a sensitivity range a serious reader can interrogate, we scope it around the decision your case has to win. See how we approach market-entry research.
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