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Quantum-Si IncQSI

Class A QSICIK 0001816431

Cash in trust

$115M

$115,003,881

Trust per share

—

Redemption value

IPO

Sep 2020

—

Combination deadline

—

Not disclosed

Filings on record

471

Latest Oct 15, 2026

Business combination

Target
Not disclosed in an indexed filing
Announced
Feb 18, 2021
Closed
Jun 16, 2021

Overview

Quantum-Si Inc is a special purpose acquisition company incorporated in Delaware and registered with the SEC under CIK 0001816431. It completed its initial public offering in Sep 2020 and listing on Nasdaq. Class A shares trade under the ticker QSI on Nasdaq. Business combination closed; the company trades under a new ticker.

How busy it has been

Filings per month since the first one. A vehicle that has gone quiet with a deadline ahead is a different proposition from one that is still working.

402002020-072026-10

471 filings in all. 12 in the last three months, against a busiest month of 40.

News on Quantum-Si Inc

Last 90 days

SEC filing history

Free tier: filings older than 24 hours
  • 8-K

    Other events

    Items 8.01, 9.01 · Accession 0001816431-26-000068

    Oct 15, 2026

    1d ago

    View on EDGAR ↗
  • 8-K

    Regulation FD disclosure

    Items 7.01, 9.01 · Accession 0001816431-26-000064

    Oct 9, 2026

    7d ago

    View on EDGAR ↗
  • 8-K

    Regulation FD disclosure

    Items 7.01, 9.01 · Accession 0001816431-26-000061

    Sep 29, 2026

    17d ago

    View on EDGAR ↗
  • 4

    Statement of changes in beneficial ownership

    Accession 0001140361-26-037481

    Sep 24, 2026

    22d ago

    View on EDGAR ↗
  • 4

    Statement of changes in beneficial ownership

    Accession 0001140361-26-037478

    Sep 24, 2026

    22d ago

    View on EDGAR ↗
  • 4

    Statement of changes in beneficial ownership

    Accession 0001140361-26-037476

    Sep 24, 2026

    22d ago

    View on EDGAR ↗
  • 144

    144 filing

    Accession 0001505034-26-000004

    Sep 24, 2026

    22d ago

    View on EDGAR ↗
  • 144

    144 filing

    Accession 0001856912-26-000003

    Sep 24, 2026

    22d ago

    View on EDGAR ↗
  • 144

    144 filing

    Accession 0001557736-26-000004

    Sep 24, 2026

    22d ago

    View on EDGAR ↗
  • SCHEDULE 13D/A

    SCHEDULE 13D/A filing

    Accession 0001140361-26-034869

    Aug 29, 2026

    1mo ago

    View on EDGAR ↗
  • 10-Q

    Quarterly report

    Accession 0001816431-26-000056

    Aug 14, 2026

    2mo ago

    View on EDGAR ↗
  • 8-K

    Current report

    Items 2.02, 9.01 · Accession 0001816431-26-000053

    Aug 14, 2026

    2mo ago

    View on EDGAR ↗
  • SCHEDULE 13G/A

    Amended beneficial ownership report (passive)

    Accession 0002012383-26-002864

    Jul 29, 2026

    2mo ago

    View on EDGAR ↗
  • 8-K

    Notice of delisting or failure to satisfy a listing rule

    Item 3.01 · Accession 0001816431-26-000049

    Jul 25, 2026

    2mo ago

    View on EDGAR ↗
  • 4

    Statement of changes in beneficial ownership

    Accession 0001140361-26-026294

    Jun 25, 2026

    3mo ago

    View on EDGAR ↗
  • 4

    Statement of changes in beneficial ownership

    Accession 0001140361-26-026290

    Jun 25, 2026

    3mo ago

    View on EDGAR ↗
  • 4

    Statement of changes in beneficial ownership

    Accession 0001140361-26-026287

    Jun 25, 2026

    3mo ago

    View on EDGAR ↗
  • 4

    Statement of changes in beneficial ownership

    Accession 0001140361-26-026285

    Jun 25, 2026

    3mo ago

    View on EDGAR ↗
  • 144

    144 filing

    Accession 0001856912-26-000002

    Jun 25, 2026

    3mo ago

    View on EDGAR ↗
  • 144

    144 filing

    Accession 0001557736-26-000003

    Jun 25, 2026

    3mo ago

    View on EDGAR ↗
  • 144

    144 filing

    Accession 0002032947-26-000002

    Jun 25, 2026

    3mo ago

    View on EDGAR ↗
  • 144

    144 filing

    Accession 0001505034-26-000003

    Jun 25, 2026

    3mo ago

    View on EDGAR ↗
  • 8-K

    Entry into a material definitive agreement

    Items 1.01, 2.03, 9.01 · Accession 0001816431-26-000046

    Jun 25, 2026

    3mo ago

    View on EDGAR ↗
  • 25-NSE

    Notification of delisting

    Accession 0001354457-26-000560

    Jun 11, 2026

    4mo ago

    View on EDGAR ↗
  • SD

    SD

    Accession 0001816431-26-000041

    May 23, 2026

    4mo ago

    View on EDGAR ↗
  • 4

    Statement of changes in beneficial ownership

    Accession 0001140361-26-022240

    May 21, 2026

    4mo ago

    View on EDGAR ↗
  • 4

    Statement of changes in beneficial ownership

    Accession 0001140361-26-022245

    May 21, 2026

    4mo ago

    View on EDGAR ↗
  • 4

    Statement of changes in beneficial ownership

    Accession 0001140361-26-022239

    May 21, 2026

    4mo ago

    View on EDGAR ↗
  • 4

    Statement of changes in beneficial ownership

    Accession 0001140361-26-022244

    May 21, 2026

    4mo ago

    View on EDGAR ↗
  • 4

    Statement of changes in beneficial ownership

    Accession 0001140361-26-022243

    May 21, 2026

    4mo ago

    View on EDGAR ↗

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Quantum-Si Inc: questions answered

What is Quantum-Si Inc (QSI)?

Quantum-Si Inc is a special purpose acquisition company incorporated in Delaware and registered with the SEC under CIK 0001816431. It completed its initial public offering in Sep 2020 and listing on Nasdaq. Class A shares trade under the ticker QSI on Nasdaq. Business combination closed; the company trades under a new ticker.

How much does Quantum-Si Inc hold in trust?

Approximately $115,003,881, as at the most recent filing on record. Trust balances move: shareholders redeem at extension votes and at the combination vote, and sponsors pay contributions in to extend. Treat the figure as a point-in-time disclosure, not a running balance.

When must Quantum-Si Inc complete a merger?

No combination deadline appears in the filings we have indexed. The date is stated in the charter and repeated in each quarterly report; where our parser could not establish it with confidence we leave it blank rather than infer one.

What happens if Quantum-Si Inc does not find a target in time?

The charter requires the vehicle to redeem 100% of the public shares and return the trust, pro rata, to public shareholders. That is the mechanism working as designed rather than a default. Founder shares and warrants are worthless in that outcome, which is why the sponsor's incentive is to get a deal done or to buy more time. Across the market, deadline lapsed without a deal; trust returned to public shareholders.

Can I redeem shares in Quantum-Si Inc, and at what price?

Public shareholders may elect to redeem in connection with a combination vote and at each extension vote, at the pro-rata trust value on the relevant record date. Redemption is a right attached to the public shares only; warrants and rights carry no claim on the trust. The mechanics and the deadline for electing are set out in the proxy statement for the vote in question.

What tickers does Quantum-Si Inc trade under?

Class A shares trade as QSI on Nasdaq. Units trade first and separate into their component securities roughly 52 days after the IPO; only the Class A shares carry the redemption right against the trust.

Is the trust value the same as the share price for Quantum-Si Inc?

No. Trust per share is a disclosed, contractual figure: what a redeeming holder receives. The market price is whatever the shares change hands at, which can sit above the trust when a deal is well received or below it when the market doubts one will close. We do not have a current quote for this vehicle, so no spread is shown.

Is Quantum-Si Inc tradeable, and where?

Yes. QSI returned a live quote of $1.12 on Nasdaq. Quotes here are delayed and refreshed on a schedule rather than streamed, so treat the figure as indicative and confirm on your own venue. Units and warrants trade under their own symbols and are quoted separately.

Is Quantum-Si Inc a good investment?

That is not a question this site answers. Quantum-Si Inc is covered here as reference data: what the company filed, when it filed it, and what the numbers in those filings say. The Edge, FOMO and Potential scores on this page are derived measures with a published formula, not ratings of investment merit: they describe the setup, and every component is shown so you can take them apart. We publish no price targets and no recommendations, and nothing here should be read as advice. The figures are a starting point for your own work, and each one carries the accession number of the filing it came from.

Where does this Quantum-Si Inc data come from?

Filings Quantum-Si Inc submitted to the SEC under CIK 0001816431: the registration statement and final prospectus for the structure, quarterly and annual reports for the trust, current reports and proxy statements for deals, votes and extensions. Trust economics are taken from the registrant's own XBRL tags rather than parsed from prose, which is why they are exact. Every filing in the history above is listed with its accession number, which identifies the document uniquely on EDGAR; Pro accounts open it directly from the row.

Compiled by the SPACListing research desk

Last reconciled Oct 16, 2026

Every figure on this page is read from documents the registrants filed with the U.S. Securities and Exchange Commission, principally the IPO prospectus (Form 424B4), quarterly and annual reports, current reports and proxy statements, the registrant's own XBRL tags for trust economics. Nothing is sourced from press coverage, from the companies themselves, or from a third-party aggregator. Where a filing does not disclose something, the field is left blank rather than estimated.

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The context around this vehicle: who else the sponsor has launched, which banks priced it, and where it sits in the wider market.