---
schema_version: "secwatch.filing_event.v1"
accession: "0001816431-26-000009"
form_type: "8-K"
ticker: "QSI"
cik: "0001816431"
company_name: "Quantum-Si Inc"
filed_at: "2026-03-03T23:59:59+00:00"
generated_at: "2026-05-15T22:20:01.806585+00:00"
event_type: "earnings"
sentiment: "neutral"
materiality_score: 0.8
calibrated_materiality_score: 0.8
confidence: "high"
source: SEC EDGAR
---

# Quantum-Si reports Q4 2025 revenue of $451k, announces Proteus list price of $425k, and provides 2026 guidance

## Summary
- Fourth quarter 2025 revenue was $451,000, gross margin 27%, and net loss $17.6 million.
- Company announced list price for Proteus platform at $425,000 and reiterated on track for year-end 2026 launch.
- Full year 2026 revenue guidance of approximately $1.0 million, adjusted operating expenses $98 million or less, total cash usage $93 million or less.
- Cash and investments as of Dec 31, 2025: $215.8 million, expected to fund operations into Q2 2028.
- Legacy litigation charges of $18.7 million impacted 2025 results.

## SEC filing metadata
- accession: 0001816431-26-000009
- form_type: 8-K
- ticker: QSI
- cik: 0001816431
- company_name: Quantum-Si Inc
- filed_at: 2026-03-03T23:59:59+00:00
- event_type: earnings
- sentiment: neutral
- materiality_score: 0.8
- calibrated_materiality_score: 0.8
- confidence: high
- sec_items: 2.02, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1816431/000181643126000009/0001816431-26-000009-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1816431/000181643126000009/qsi-20260303.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001816431-26-000009
- JSON: https://secwatch.observer/filing/0001816431-26-000009.json
- Plain text: https://secwatch.observer/filing/0001816431-26-000009.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.