Form
SCHEDULE 13D/A
Active or control-oriented beneficial ownership filing.
Ph.D. Jonathan M. Rothberg - 27 Dec 2024 SCHEDULE 13D/A Report for Quantum-Si Inc Class A common stock, par value $0.0001 per share, Class B common stock, par value $0.0001 per share (QSI)
- Filing manager
- Ph.D. Jonathan M. Rothberg
- Reporting owner
- ROTHBERG JONATHAN M
- Beneficially owned shares
- 19,937,500 shares
- Large-stake signal
-
Ownership
100%Beneficial ownership of this reported class.
Shares
19,937,500 sharesShares beneficially owned as disclosed.
Event date
27 Dec 2024Date tied to the ownership event or amendment.
Accepted by SEC
31 Dec 2024EDGAR acceptance date.
How to read this large-stake filing
- Schedule 13D/G filings focus on beneficial ownership stakes, not a full portfolio.
- Compare this filing with the holder history and issuer page before treating the percentage as a current position.
- Use amendments to understand whether the disclosed stake increased, decreased, or changed reporting status.
- Class ownership
- 100%
- Symbol
- QSI
- Shares outstanding
- 19,937,500 shares
- SEC form
- SCHEDULE 13D/A
- Accepted by SEC
- 31 Dec 2024, 20:30:05 UTC
- Event date
- 27 Dec 2024
- Next SEC filing
- 11 Sep 2025
- Source filing
- View source filing
Ownership signal
CIK-linked ownership evidence from parsed SEC filings.
2 signals
Subject security
Names, identifiers, and filing context for this profile.
2 source fields
Source evidence
Original filing metadata and source links for verification.
5 source fields
Key filing fact
Ph.D. Jonathan M. Rothberg disclosed 100% ownership in Quantum-Si Inc Class A common stock, par value $0.0001 per share, Class B common stock, par value $0.0001 per share (QSI) on 27 Dec 2024.
Key facts
- Ph.D. Jonathan M. Rothberg filed SCHEDULE 13D/A for Quantum-Si Inc Class A common stock, par value $0.0001 per share, Class B common stock, par value $0.0001 per share (QSI).
- Disclosed ownership: 100%.
- Date of event: 27 Dec 2024.
Change
- No earlier schedule filing is available for direct comparison.
- Current filing was accepted on 31 Dec 2024, 20:30.
Research use
- This page turns one Schedule 13D/G filing into a quick large-stake read before the raw reporting-person rows.
- Use the linked SEC filing as the source of truth for ownership percentages, shares, and reporting-party details.
Evidence
Backed by Schedule 13D/13G
View source filing
Beneficial ownership values are sourced from the original SEC Schedule 13D/13G filing.
Reporting persons
Disclosed reporting parties (6)
Names, ownership percentages, voting power, signatures, titles, and CIKs as disclosed in this Schedule 13D/G filing.
| Name | Ownership | Shares owned | Sole voting power | Shared voting power | Signature | Title | CIK |
|---|---|---|---|---|---|---|---|
| ROTHBERG JONATHAN M | 12% | 14,163,134 | 11,972,645 | 2,190,489 | /s/ Jonathan M. Rothberg | Jonathan M. Rothberg, Ph.D. | 0001076352 |
| ROTHBERG JONATHAN M | 100% | 19,937,500 | 19,937,500 | 0 | /s/ Jonathan M. Rothberg | Jonathan M. Rothberg, Ph.D. | |
| 23rd Century Capital LLC | 1.6% | 1,917,067 | 1,917,067 | /s/ Jonathan M. Rothberg | Jonathan M. Rothberg, Ph.D., Member | ||
| 2012 JMR Trust Common, LLC | 2.2% | 2,723,841 | 2,723,841 | /s/ Jonathan M. Rothberg | Jonathan M. Rothberg, Ph.D., Manager | ||
| 4C Holdings I, LLC | 90% | 17,943,750 | 17,943,750 | /s/ Jonathan M. Rothberg | Jonathan M. Rothberg, Ph.D., Manager | ||
| 4C Holdings V, LLC | 10% | 1,993,750 | 1,993,750 | /s/ Jonathan M. Rothberg | Jonathan M. Rothberg, Ph.D., Manager |
CIK / CUSIP context first