Quick Takeaways
- BlackRock Portfolio Management LLC filed SCHEDULE 13G/A for MASIMO CORP Common Stock (MASI).
- Disclosed ownership: 0.2%.
- Date of event: 31 Mar 2026.
BlackRock Portfolio Management LLC - 31 Mar 2026 SCHEDULE 13G/A Report for MASIMO CORP Common Stock (MASI)
- Filing Manager
- BlackRock Portfolio Management LLC
- Reporting Manager
- BlackRock Portfolio Management LLC
- Security
- MASIMO CORP Common Stock
- Symbol
- MASI
- Disclosed Ownership
- 116,871 shares
- Ownership
- 0.2%
- Form type
- SCHEDULE 13G/A
- Filing time
- 30 Apr 2026, 16:37:27 UTC
- Date of event
- 31 Mar 2026
- Previous filing
- 21 Jan 2026
- SEC
- View on sec.gov
Quoteable Key Fact
"BlackRock Portfolio Management LLC disclosed 0.2% ownership in MASIMO CORP Common Stock (MASI) on 31 Mar 2026."
What Changed
- Previous schedule filing date: 21 Jan 2026.
- Current filing was accepted on 30 Apr 2026, 16:37.
Why This Matters
- This page explains what this Schedule 13D/13G filing tells you before manager-level rows.
- You can verify ownership claims directly against the original SEC filing.
Source Evidence
Backed by Schedule 13D/13G
See Original Filing
Beneficial ownership values are sourced from the original SEC Schedule 13D/13G filing.
Reporting Managers (1)
| Name | Ownership | Shares Owned | sole voting power | shared voting power | Signature | Title | CIK |
|---|---|---|---|---|---|---|---|
| BlackRock Portfolio Management LLC | 0.2% | 116,871 | 94,486 | 0 | Spencer Fleming | Managing Director |