Quantum-Si Inc has 5 Schedule 13D or 13G filings on record since 2025-07-29. 1 holder's latest filing reports 5% or more of class a common stock, par value $0.0001 per share, class b common stock, par value $0.0001 per share. Each figure below is the holder's own, as filed, with the filing linked.
Holders
| Holder | Percent | Shares | Latest | Event date |
|---|---|---|---|---|
| Rothberg Jonathan M | 100% | 14,376,415 | SCHEDULE 13D/A, 2026-08-28 | 2026-08-26 |
| The Vanguard Group | 4.77% | 8,714,507 | SCHEDULE 13G/A, 2025-10-30 | 2025-09-30 |
| BlackRock, Inc. | 2.3% | 4,598,208 | SCHEDULE 13G/A, 2026-07-29 | 2026-06-30 |
Purpose of Transaction (Item 4)
Rothberg Jonathan M
In connection with estate planning, entities owned by trusts created for the benefit of Dr. Jonathan Rothberg's children have entered into a trading plan pursuant to Rule 10b5-1 under the Securities Exchange Act of 1934, as amended (the "Plan"), a copy of which is attached hereto as Exhibit 6. Pursuant to the Plan, sales of up to 8,947,746 shares of Class A common stock may be effected during the plan sales period beginning following the cooling-off period contained in Rule 10b5-1(c) on January 15, 2027 and ending on January 15, 2028 in accordance with the terms and conditions of the Plan. The sale of shares of Class A common stock under the Plan is subject to minimum price parameters included in the Plan, and there is no assurance that any shares of Class A common stock will be sold under the Plan.Item 4 of the SCHEDULE 13D/A filed 2026-08-28
Timeline
| Filed | Holder | Percent | Filing |
|---|---|---|---|
| 2025-07-29 | The Vanguard Group | 5.3% | SCHEDULE 13G |
| 2025-09-11 | Rothberg Jonathan M | 100% | SCHEDULE 13D/A |
| 2025-10-30 | The Vanguard Group | 4.77% | SCHEDULE 13G/A |
| 2026-07-29 | BlackRock, Inc. | 2.3% | SCHEDULE 13G/A |
| 2026-08-28 | Rothberg Jonathan M | 100% | SCHEDULE 13D/A |
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Where this comes from
Anyone who comes to own more than 5% of a class of a listed company's voting shares has to tell the SEC. A holder who may seek to change or influence the company files Schedule 13D, and has to say in Item 4, "Purpose of Transaction", what it intends to do. A holder with no such intent, such as many index and passive funds, may file the shorter Schedule 13G. Both are amended when the stake changes, including when it falls below 5%.
Every row here is one of those filings, linked to the filing itself. Percentages and share counts are exactly as the holder filed them, for the holder the filing names; an amendment showing a lower figure is shown as filed. Item 4 text is quoted word for word. Where a 13D's Item 4 contains a sentence stating a definite intent to influence the company, that sentence is marked and quoted; the page does not describe the holder or its motives beyond the words it filed. Nothing here is investment advice.