Quantum Ledger
Vol. III·Sector Directory·Companies
41 names · listed & material private
Boulder · Colorado
updated continuously

The quantum cohort

A screener for the quantum economy — every public ticker and material private actor, ranked by the Ledger Score and read against the same set of editorial questions.

The most useful screener for a pre-revenue sector is the one that lets you sort by conviction, not market cap.

— the editorial premise of this directory

The cohort below is the universe the Ledger watches every weekday. It is curated, not exhaustive: each name is here because it is either publicly listed, materially funded, or carrying a technical claim other operators take seriously. The Ledger Score is a composite — capital, technical milestones, sentiment, policy, talent, patents — and is not a recommendation. Treat the rankings as a starting point, the per-company profile as the actual argument.

Filter by ownership=all, modality=superconducting, or change the sort order=score. The directory state lives in the URL — copy the address bar and you've shared the screen.

Most active · today's session

Where the cohort is moving

The screener · 5 of 41 match

Ranked by Ledger conviction

  1. 01
    IBM (Quantum)IBM

    Sets the field's calendar — largest installed base, most credible roadmap (Heron → Nighthawk → Loon → Kookaburra → Starling).

    Superconducting

    Armonk, NY, USA

    $245.0B
    +0.4%
    85/100
  2. 02
    Google Quantum AIGOOGL

    Willow set the QEC bar (below-threshold error correction, Dec 2024); Quantum Echoes (Oct 2025) made the first verifiable advantage claim.

    Superconducting

    Santa Barbara, CA, USA

    $2.2T
    -1.1%
    72/100
  3. 03
    IQM Quantum ComputersPRIVATEPrivate

    Largest European on-prem quantum installer; 15 systems shipped to HPC centers; €275M Series B was the largest in industry history.

    Superconducting

    Espoo, Finland

    n/a
    n/a
    70/100
  4. 04
    Origin QuantumPRIVATEPrivate

    China's national quantum champion — only Chinese company with a complete vertical stack; STAR Market IPO in counseling.

    Superconducting

    Hefei, China

    n/a
    n/a
    56/100
  5. 05
    Rigetti ComputingRGTI

    Cash-rich superconducting modular-chiplet bet, but revenue is shrinking and competing directly with IBM at a fraction of the scale.

    Superconducting

    Berkeley, CA, USA

    $6.8B
    -7.4%
    42/100

A cohort is not an index. We omit names that publish only aspirational roadmaps; we include names with no revenue if a sovereign technical buyer has audited the science.

— directory methodology