# Method

Cohort: organisations founded 2015 to 2017 whose last round is pre-seed, seed or angel,
or whose last round is Series A to J or any post-IPO round (post-IPO debt included)
with at least two rounds on file. Two rounds do not prove a seed round. Last rounds
of other debt, grant, private equity, corporate, crowdfunding or unlabelled
series are left out, because they give no stage. Stage = last round type.
Acquired = a non-empty acquisition date. Closed = operating status "closed".

Website check: the 18,047 companies with no round after seed that are not acquired
and not closed; 143 without a usable domain dropped; 1,500 drawn at random
(seed 7) from the remaining 17,904.

Each homepage was fetched over HTTPS then HTTP through a rotating proxy, full HTML read.
States:
- Domain no longer registered: NXDOMAIN or no working nameservers, confirmed on a
  second resolver.
- No working site: domain resolves, no page after a retry.
- Parked or for sale: marketplace names or for-sale phrases in the HTML.
- Someone else's website / placeholder / could not tell / same company: verdict of
  Gemini 3.5 Flash-Lite given company name, description, page title, final URL and the
  last 600 characters of page text. All 30 gambling verdicts read by hand; two moved back
  to same company.
- Copyright year: highest year after (c), © or "copyright" in the page, or read
  by the model from the footer. Pages that compute the year in JavaScript count as no
  year. 2024 or older counts as stale.

Margin on a share p from the 1,500 sample: 1.96 * sqrt(p(1-p)/1500), about 2.5 points
at 51%.