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=listed, 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 pre-IPO public-market proxy for Quantinuum — ~54% owner ahead of the Quantinuum (QNT) listing at $20B+ target valuation.
Post-quantum cryptography pure-play — bets symmetric key agreement beats NIST PQC algorithms in enterprise procurement.
The only public quantum pure-play crossing $100M revenue; vertically integrating via the $1.8B SkyWater acquisition.
The screener · 3 of 41 match
Ranked by Ledger conviction
- 01IBM (Quantum)IBM
Sets the field's calendar — largest installed base, most credible roadmap (Heron → Nighthawk → Loon → Kookaburra → Starling).
Superconducting
Armonk, NY, USA
$245.0B+2.3%85/100 - 02Google 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+4.8%72/100 - 03Rigetti 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+5.9%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