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startup ideas · stealth

Stealth startups, measured

A stealth startup builds without telling the market what it builds: no product page, a one-line placeholder, job posts under a generic name. It is a common phrase and a rare condition. Across the 20,502 accelerator companies MarkosWeb tracks, 10 describe themselves as stealth, and 55 companies from the 2025-26 cohorts are listed without a website at all.

10

call themselves stealth

55

2025-26 entries without a website

235

listed so far in YC S26

20,502

companies tracked

What stealth mode is, and what it costs

Why founders do it. To keep a competitor from seeing the approach before it works, to control the moment of launch, or because the product does not exist yet and a placeholder is more honest than a pitch. Partial stealth - a named company with a deliberately vague one-liner - is far more common than total secrecy.

What it costs. No customer feedback from the market at large, harder hiring (candidates cannot see what they would build), and an unforgiving launch: the first public version has to carry the whole story. The accelerator directories below show how short the stealth window usually is - most placeholders become real one-liners within a batch.

How to read the lists. Self-described stealth entries are companies that chose the word. Entries without a website are a weaker signal: 48 of the 55 are 500 Global records where the directory often omits the site, which is a data gap, not secrecy. The Y Combinator and Techstars entries without a site are the ones worth a second look.

Companies that call themselves stealth

Name or one-liner contains the word. Most recent cohort first; names link to the MarkosWeb domain report where a domain is known.

Listed before they had a website: 2025-26 cohorts

ProgramNo website
500 Global48
Techstars5
Y Combinator2

The Y Combinator, Techstars and a16z speedrun entries in that group:

Where stealth companies surface first

Y Combinator publishes companies to its directory continuously while a batch is still forming, often before the company has a product page. That feed is the best place to watch stealth companies become public. The S26 batch has 235 companies listed so far. Batch Live tracks it as it fills; Trajectory shows which placeholders turned into real companies and which were delisted.

More startup ideas by angle

Validate any of them: Idea Check shows who already builds it; Idea Lab writes concepts from a cluster's data; Chat matches ideas to what you can build.