Latest Period
Q1 2026
Security Snapshot
Atrium Therapeutics, Inc. - Common Stock, par value $0.001 per share (RNA) Institutional Ownership
CUSIP: 04965N104
13F Institutional Holders and Ownership History for Q1 2026
Institutions Reporting
158
Shares (Excl. Options)
14,820,324
Price
$13.37
Save this security page for your next review
Keep this CUSIP in your watchlists so you can revisit quarter changes from one place. If you create an account from here, we will bring you back after verification.
- Security type / class
- Equity / Common Stock, par value $0.001 per share
- Symbol
- RNA on Nasdaq
- All holders as of 31 Mar 2026
- Q1 2026
- Total 13F shares
- 14,820,324
- Total 13F value
- $198,157,957
- Portfolio coverage rank
- 0%
- Share change
- +13,162,095
- Value change
- +$175,987,435
- Number of holders
- 158
- Shares outstanding
- 15,430,393
- SEC-reported price per share
- $13.14
Latest holder snapshot
5 signals
Issuer context
Names, identifiers, and filing context for this profile.
2 identity fields
13F Shares, Excluding Options vs Price
13F Value, Excluding Options
Total Investors
Key facts
- RNA - Atrium Therapeutics, Inc. - Common Stock, par value $0.001 per share is tracked under CUSIP 04965N104.
- 158 institutions reported positions in Q1 2026.
- 1 significant owner is listed from Schedule 13D/13G reporting.
Change
- Latest quarter on this page is Q1 2026.
- Additional quarter-over-quarter change detail appears as history expands.
Research use
- You can quickly see who holds this security, then open quarter and manager detail pages for full evidence.
- 13F and Schedule 13D/13G sections are kept together so you can cross-check institutional and beneficial ownership context.
Evidence
Source: SEC Form 13F
Open SEC evidence
Latest holder context comes from 158 institutions filings for Q1 2026.
Security key
04965N104
Latest holder period
Q1 2026
13F holders
158
13D/G owners
1
CIK / CUSIP context first
Open Q1 2026 holders
RNA full holder history
Atrium Therapeutics, Inc. SEC filings
Atrium Therapeutics, Inc. company facts
Atrium Therapeutics, Inc. insider transactions
Broader feeds
Recent Quarterly Holder Reports
Open recent reporting periods for CUSIP 04965N104:
13D/G owners
Significant owners
Large-stake holder rows connected to Schedule 13D/G evidence.
Rows
1
Security
RNA
| Filer | Ownership | Change % | Holdings Value | Net Change | Nb Shares | Change % | Reporting Name | Report Period |
|---|---|---|---|---|---|---|---|---|
| RA CAPITAL MANAGEMENT, L.P. | 5.6% | $10,982,736 | 864,102 | RA Capital Management, L.P. | 31 Mar 2026 |
As of 31 Mar 2026, 158 institutional investors reported holding 14,820,324 shares of Atrium Therapeutics, Inc. - Common Stock, par value $0.001 per share (RNA). This represents 96% of the company’s total 15,430,393 outstanding shares.
13F concentration
Top 25 institutional shareholders
Largest 13F positions for this security by reported shares and value.
Top holder share
70%
| Institution | Ownership % | Shares Held | Share Change % | Portfolio % | Holdings Value |
|---|---|---|---|---|---|
| PRICE T ROWE ASSOCIATES INC /MD/ | 10% | 1,553,210 | 0% | $20,767,000 | |
| BlackRock, Inc. | 7.8% | 1,205,291 | 0% | $16,114,735 | |
| RA CAPITAL MANAGEMENT, L.P. | 5.6% | 864,102 | 0.12% | $11,553,044 | |
| VANGUARD CAPITAL MANAGEMENT LLC | 4.1% | 626,869 | 0% | 0% | $8,381,239 |
| TIG Advisors, LLC | 3.9% | 607,552 | 0.39% | $8,122,970 | |
| Pentwater Capital Management LP | 3.9% | 602,649 | 0.06% | $8,057,417 | |
| O'Connor Alternative Investments LLC | 3.7% | 578,011 | 0% | 0.68% | $7,728,007 |
| Sessa Capital IM, L.P. | 3.6% | 551,391 | 0.14% | $7,372,098 | |
| GOLDMAN SACHS GROUP INC | 2.3% | 349,950 | 0% | $4,678,831 | |
| FARALLON CAPITAL MANAGEMENT LLC | 2.3% | 349,360 | 0.03% | $4,670,943 | |
| VANGUARD PORTFOLIO MANAGEMENT LLC | 2.2% | 344,369 | 0% | 0% | $4,604,214 |
| GEODE CAPITAL MANAGEMENT, LLC | 2.1% | 319,831 | 0% | $4,277,244 | |
| 683 Capital Management, LLC | 1.9% | 300,000 | 0.37% | $4,011,000 | |
| Bellevue Group AG | 1.7% | 263,096 | 0.08% | $3,517,594 | |
| STATE STREET CORP | 1.7% | 257,086 | 0% | $3,437,240 | |
| Weiss Asset Management LP | 1.6% | 240,701 | 0.06% | $3,218,172 | |
| CANTOR FITZGERALD, L. P. | 1.5% | 235,637 | 0.11% | $3,150,467 | |
| Balyasny Asset Management L.P. | 1.5% | 235,115 | 0.01% | $3,143,488 | |
| Squarepoint Ops LLC | 1.5% | 231,466 | 0.01% | $3,094,700 | |
| Arbiter Partners Capital Management LLC | 1.5% | 230,000 | 2.1% | $3,075,100 | |
| MILLENNIUM MANAGEMENT LLC | 1.2% | 190,859 | 0% | $2,551,785 | |
| ADAGE CAPITAL PARTNERS GP, L.L.C. | 1.2% | 183,580 | 0% | $2,454,465 | |
| Slotnik Capital, LLC | 1.2% | 180,945 | 0.72% | $2,419,235 | |
| AQR Arbitrage LLC | 1.2% | 179,713 | 0.04% | $2,402,763 | |
| TWO SIGMA INVESTMENTS, LP | 1.2% | 178,560 | 0% | $2,387,347 |
Quarter history
Institutional holders across reporting periods
Holder count, reported shares/value, and median price by quarter.
Periods
1
Latest
Q1 2026
Rows shown
1-1 of 1
| Period | 13F Shares, Excl. Options | Value, Excl. Options | Value Change | Price (Median) | Investors |
|---|---|---|---|---|---|
| 2026 Q1 | 14,820,324 | $198,157,957 | +$175,987,435 | $13.37 | 158 |