SEPTInvestingStart Free

QSI SCHEDULE 13D/A: Insider sale planned

Filed with the SEC on · accession 0001140361-26-034869

QSI filed a SCHEDULE 13D/A (schedule 13d/a) with the SEC on Aug 28, 2026. A report the company filed with the SEC (the US market regulator). The stock moved -2.9% by the first close after the filing.

Summary of the filing

Jonathan Rothberg, an affiliate of Quantum-Si Incorporated, adopted a Rule 10b5-1 sales plan to sell up to 8,947,746 shares of QSI common stock beginning January 15, 2027, with sales running through January 15, 2028.

For details, click here →

Key details

Maximum number of shares subject to the Rule 10b5-1 sales plan$8.9M
IssuerQuantum-Si Incorporated
Broker acting as agent for the seller under the sales planJefferies LLC
Entity on whose behalf jonathan rothberg is actingNVR TR, LLC
Entity on whose behalf jonathan rothberg is actingJNR TR, LLC
Entity on whose behalf jonathan rothberg is actingJAR TR, LLC
Entity on whose behalf jonathan rothberg is actingEJR TR, LLC
Entity on whose behalf jonathan rothberg is actingGBR TR, LLC
Section 16 affiliate / sellerJonathan Rothberg
General counsel, quantum-si incorporatedChristian LaPointe

How QSI stock reacted

Close before

$0.80

Aug 27, 2026

First close after

-2.88%

$0.78

5 trading days

-5.24%

$0.76

Since filing

+65.61%

$1.33

✦ Ask GOAX AI about this filing — what it means for QSI, what changed since its last filings and what to watch next.

Try it free for 7 days

🔔 Want to stay updated on new SEC filings for QSI?

Click here

Frequently asked questions

What did QSI file with the SEC on Aug 28, 2026?

QSI filed a SCHEDULE 13D/A (Insider sale planned). Jonathan Rothberg, an affiliate of Quantum-Si Incorporated, adopted a Rule 10b5-1 sales plan to sell up to 8,947,746 shares of QSI common stock beginning January 15, 2027, with sales running through January 15, 2028.

How do I read a SCHEDULE 13D/A?

A report the company filed with the SEC (the US market regulator). Start with the summary, then the key amounts and names. Compare it with the company’s earlier filings.

Why are SEC filings important?

Public companies must tell the SEC about anything that can change their value — results, leadership changes, big deals, new shares, bankruptcy. Filings are the official source, often before the news. A SCHEDULE 13D/A (schedule 13d/a): A report the company filed with the SEC (the US market regulator).

How did QSI stock react to this filing?

QSI closed at $0.80 before the filing and $0.78 on Aug 28, 2026 (-2.88%). Five trading days later: $0.76 (-5.24%).

Other QSI SEC filings

Get alerts when QSI files with the SEC, plus live charts, key levels and news for 13,000+ stocks.

Try SEPT free for 7 days
QSI overviewQSI analysisQSI newsLatest SEC filings