A share price is not a funding total · Why private companies get their own block · Currency, timestamps and stale quotes · What counts as a pure play · How to read the two tables together · What would change this ranking
What this ranking measures
This table ranks companies whose primary business is quantum technology and whose equity is publicly traded. Market capitalisation is share price multiplied by shares outstanding; it is a claim on the whole company, not a measure of cash raised, revenue or technical progress.
It cannot be compared with the funding ranking on this site. Disclosed financing is a cumulative inflow recorded when a round is announced; market capitalisation is a live market price that moves every trading day. Adding the two together, or sorting them in one table, would produce a number with no meaning.
Private companies have no market capitalisation at all. PsiQuantum, Quantinuum, IQM, Pasqal and most of this site's funding leaderboard are privately held. They appear in a separate comparison block below, ranked by disclosed financing, so the distinction stays visible.
Currency: all figures are normalised to US dollars. A-share and other non-USD quotes need an explicit FX rate and date attached to each row; until that feed is wired up, no non-USD row is presented as a current quote.
Scope: pure-play quantum companies only. Diversified semiconductor, defence and telecom groups with a quantum research programme or a supply-chain relationship are excluded, because their market capitalisation mostly reflects other businesses.
A share price is not a funding total
Market capitalisation is the quoted share price multiplied by shares outstanding. It is a live estimate of the whole equity, revised every time the market moves. Disclosed financing is a cumulative inflow, recorded on the date a round or an offering was announced. The first number can fall tomorrow; the second only grows when a new instrument is reported.
That asymmetry is why the two never appear in the same column on this site. Adding a latest valuation to lifetime funding produces a figure that is neither a valuation nor a total raised, and sorting companies by it produces a ranking no one can reproduce. Several aggregators do exactly that, which is one reason a reader may see very different totals elsewhere.
Why private companies get their own block
Most of the companies on this site's funding leaderboard are privately held: PsiQuantum, Quantinuum, IQM, Pasqal and many others have no observable share price at all. A valuation from a funding round is a negotiated number attached to one transaction, not a continuously quoted market price, and it says nothing about what a minority stake could be sold for today.
They are therefore listed below in a separate comparison block, ranked by disclosed financing and explicitly labelled as non-market figures. Keeping the blocks apart is a design decision, not a temporary workaround: it stops a casual reader from concluding that a private company is 'worth more' than a listed one on the strength of two incompatible numbers.
Currency, timestamps and stale quotes
Every figure here is normalised to US dollars. A quote in RMB, Swiss francs or euros needs an exchange rate and the date of that rate attached to the row, otherwise the ranking silently compares prices converted at different moments. Until a dated feed is wired in, no non-USD row is presented as a current quote and its conversion caveat is printed on the card.
A market-cap ranking is a time series. The funding ledger on this site is cumulative, so overwriting yesterday's total with today's is harmless; overwriting a market-cap history is not. The feed contract below requires a dated asOf per row, an exchange trading-calendar check, and an explicit stale marker for any quote older than the page date. A row carried forward without a timestamp is a fabricated quote.
What counts as a pure play
The table covers companies whose primary business is quantum technology and whose equity is publicly traded. Diversified semiconductor, defence and telecom groups with a research programme, a supply-chain relationship or a quantum-branded product line are excluded: their market capitalisation mostly reflects other businesses, and including them would turn a quantum ranking into a large-cap index with a few quantum footnotes.
Boundary cases are flagged rather than quietly dropped. A secure-chip company whose product is post-quantum cryptography, for example, is a quantum-adjacent listing rather than a quantum hardware company; it carries a scope-review note so the inclusion rule can be challenged with evidence. Scope disputes are recorded on the corrections log, not settled by editing a row.
How to read the two tables together
A large market capitalisation next to a modest financing total usually means public markets are pricing a technical option that venture investors funded cheaply years earlier. The reverse — heavy disclosed financing and a small quoted market value — can reflect dilution, a listing that repriced the company, or a gap between a private round's narrative and what public buyers will pay. Neither reading is a verdict on the science.
The useful comparison is directional: it tells you where expectations sit today and how much cash was raised to get there. It does not tell you which architecture will win, and this site does not publish a score that claims to. Every row links to the company page where its financing events are listed individually with their own editorial note.
What would change this ranking
Share issuance, buybacks, a secondary listing, a spin-out of the quantum unit, or a sustained repricing after a technical milestone would all move a row without any new financing being announced. A company going private would remove it entirely while leaving its funding history intact. Those are corporate events, not funding events, which is precisely why the section maintains its own change record instead of inheriting the funding scanner's log.
How these figures will be sourced
Every monetary value on this page is currently an illustrative placeholder labelled DEMO. Once a dated quote feed is connected, each row will carry its quote date, currency, USD conversion rate and conversion date where applicable, shares outstanding, and a named source.
A market-cap ranking is a time series, so it needs a history file rather than a single overwritten snapshot: readers should be able to see how a company's position changed. The funding ranking on this site is cumulative and has no such requirement.
Quote timestamps, exchange trading days and trading halts all matter. A quote older than the page's snapshot date would be marked stale rather than carried forward silently.
Questions readers ask
Why is this ranked separately from the funding leaderboard?
Because the two numbers measure different things on different clocks. Funding is a cumulative, event-dated inflow; market capitalisation is a live price for the entire equity. Combining them creates a figure with no defined meaning.
Are these real market prices?
Not yet. Company names, tickers and exchanges are real public facts, but every monetary value on this page is an illustrative placeholder labelled DEMO. A dated, sourced quote feed is required before these can be read as live quotes.
Why is a large private company missing from the top?
It has no listed share price. Private companies are shown in a separate block ranked by disclosed financing, with a label that states the different basis explicitly.
How often will this update once live?
Market capitalisation changes every trading day. The feed contract requires a dated snapshot per row and a retained history file, so the site shows how positions changed rather than silently replacing yesterday's quote.
The practical takeaway
The practical reading is simple: use this table for what public markets currently think, use the funding ranking for what has actually been raised, and never treat the difference between them as an error to be reconciled.