Quantum-Si IncQSI
Cash in trust
$115M
$115,003,881
Trust per share
—
Redemption value
IPO
Sep 2020
—
Combination deadline
—
Not disclosed
Filings on record
462
Latest Aug 28, 2026
Business combination
- Target
- Not disclosed in an indexed filing
- Announced
- Feb 18, 2021
- Closed
- Jun 15, 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.
News on Quantum-Si Inc
Last 90 daysNothing in the last 90 days that names this vehicle. We attribute a story only when the release carries the ticker or the registered name, so an empty section means no press release or wire story matched — not that nothing was published. The filings below are the primary record either way.
SEC filing history
Free tier: filings older than 24 hours- SCHEDULE 13D/A
SCHEDULE 13D/A filing
Accession 0001140361-26-034869
- 10-Q
Quarterly report
Accession 0001816431-26-000056
- 8-K
Current report
Items 2.02, 9.01 · Accession 0001816431-26-000053
- SCHEDULE 13G/A
Amended beneficial ownership report (passive)
Accession 0002012383-26-002864
- 8-K
Notice of delisting or failure to satisfy a listing rule
Item 3.01 · Accession 0001816431-26-000049
- 4
Statement of changes in beneficial ownership
Accession 0001140361-26-026294
- 4
Statement of changes in beneficial ownership
Accession 0001140361-26-026290
- 4
Statement of changes in beneficial ownership
Accession 0001140361-26-026287
- 4
Statement of changes in beneficial ownership
Accession 0001140361-26-026285
- 144
144 filing
Accession 0001856912-26-000002
- 144
144 filing
Accession 0001557736-26-000003
- 144
144 filing
Accession 0002032947-26-000002
- 144
144 filing
Accession 0001505034-26-000003
- 8-K
Entry into a material definitive agreement
Items 1.01, 2.03, 9.01 · Accession 0001816431-26-000046
- 25-NSE
Notification of delisting
Accession 0001354457-26-000560
- SD
SD
Accession 0001816431-26-000041
- 4
Statement of changes in beneficial ownership
Accession 0001140361-26-022240
- 4
Statement of changes in beneficial ownership
Accession 0001140361-26-022245
- 4
Statement of changes in beneficial ownership
Accession 0001140361-26-022239
- 4
Statement of changes in beneficial ownership
Accession 0001140361-26-022244
- 4
Statement of changes in beneficial ownership
Accession 0001140361-26-022243
- 4
Statement of changes in beneficial ownership
Accession 0001140361-26-022238
- 4
Statement of changes in beneficial ownership
Accession 0001140361-26-022242
- 4
Statement of changes in beneficial ownership
Accession 0001140361-26-022237
- 4
Statement of changes in beneficial ownership
Accession 0001140361-26-022241
- 8-K
Submission of matters to a vote of security holders
Item 5.07 · Accession 0001816431-26-000037
- 10-Q
Quarterly report
Accession 0001816431-26-000034
- 8-K
Current report
Items 2.02, 9.01 · Accession 0001816431-26-000032
- 4
Statement of changes in beneficial ownership
Accession 0001140361-26-016155
- 4
Statement of changes in beneficial ownership
Accession 0001140361-26-016152
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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 $0.78 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 Sep 17, 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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Continue reading
The context around this vehicle: who else the sponsor has launched, which banks priced it, and where it sits in the wider market.
All completed de-spac transactions
Business combination closed; the company trades under a new ticker.
Deadline calendar
Which sponsors are running out of time, and when the extension votes land.
What is a SPAC?
The structure, the economics and where the risks actually sit.
SPAC glossary
Every term in a blank-check filing, defined the way practitioners use it.
How this data is built
Coverage universe, ingestion, normalisation, lifecycle classification and known limits.