Quick Takeaways
- VIKING GLOBAL INVESTORS LP filed SCHEDULE 13G/A for Sionna Therapeutics, Inc. Common Stock, $0.001 par value per share (SION).
- Disclosed ownership: 7.1%.
- Date of event: 31 Mar 2026.
VIKING GLOBAL INVESTORS LP - 31 Mar 2026 SCHEDULE 13G/A Report for Sionna Therapeutics, Inc. Common Stock, $0.001 par value per share (SION)
- Filing Manager
- VIKING GLOBAL INVESTORS LP
- Reporting Manager
- VIKING GLOBAL INVESTORS LP
- Symbol
- SION
- Shares outstanding
- 45,002,549 shares
- Disclosed Ownership
- 3,195,181 shares
- Ownership
- 7.1%
- Form type
- SCHEDULE 13G/A
- Filing time
- 15 May 2026, 17:48:36 UTC
- Date of event
- 31 Mar 2026
- Previous filing
- 14 Feb 2025
- SEC
- View on sec.gov
Quoteable Key Fact
"VIKING GLOBAL INVESTORS LP disclosed 7.1% ownership in Sionna Therapeutics, Inc. Common Stock, $0.001 par value per share (SION) on 31 Mar 2026."
What Changed
- Previous schedule filing date: 14 Feb 2025.
- Current filing was accepted on 15 May 2026, 17:48.
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 (10)
| Name | Ownership | Shares Owned | sole voting power | shared voting power | Signature | Title | CIK |
|---|---|---|---|---|---|---|---|
| VIKING GLOBAL INVESTORS LP | 7.1% | 3,195,181 | 0 | 3,195,181 | /s/ Scott M. Hendler | Scott M. Hendler on behalf of VIKING GLOBAL INVESTORS LP (1)(2) | |
| Viking Global Opportunities Parent GP LLC | 7.1% | 3,195,181 | 0 | 3,195,181 | /s/ Scott M. Hendler | Scott M. Hendler on behalf of Viking Global Opportunities Parent GP LLC (1)(2) | |
| Viking Global Opportunities GP LLC | 4.5% | 2,039,801 | 0 | 2,039,801 | /s/ Scott M. Hendler | Scott M. Hendler on behalf of Viking Global Opportunities GP LLC (1)(2) | |
| Viking Global Opportunities Portfolio GP LLC | 4.5% | 2,039,801 | 0 | 2,039,801 | /s/ Scott M. Hendler | Scott M. Hendler on behalf of Viking Global Opportunities Portfolio GP LLC (1)(2) | |
| Viking Global Opportunities Illiquid Investments Sub-Master LP | 4.5% | 2,039,801 | 0 | 2,039,801 | /s/ Scott M. Hendler | Scott M. Hendler on behalf of Viking Global Opportunities Illiquid Investments Sub-Master LP (1)(2) | |
| Viking Global Opportunities Drawdown GP LLC | 2.6% | 1,155,380 | 0 | 1,155,380 | /s/ Scott M. Hendler | Scott M. Hendler on behalf of Viking Global Opportunities Drawdown GP LLC (1)(2) | |
| Viking Global Opportunities Drawdown Portfolio GP LLC | 2.6% | 1,155,380 | 0 | 1,155,380 | /s/ Scott M. Hendler | Scott M. Hendler on behalf of Viking Global Opportunities Drawdown Portfolio GP LLC (1)(2) | |
| Viking Global Opportunities Drawdown (Aggregator) LP | 2.6% | 1,155,380 | 0 | 1,155,380 | /s/ Scott M. Hendler | Scott M. Hendler on behalf of Viking Global Opportunities Drawdown (Aggregator) LP (1)(2) | |
| HALVORSEN OLE ANDREAS | 7.1% | 3,195,181 | 0 | 3,195,181 | /s/ Scott M. Hendler | Scott M. Hendler on behalf of O. Andreas Halvorsen (1) | |
| Shabet Rose Sharon | 7.1% | 3,195,181 | 0 | 3,195,181 | /s/ Scott M. Hendler | Scott M. Hendler on behalf of Rose S. Shabet (2) |