Latest Period
Q2 2026
CUSIP: 829401108
Latest Period
Q2 2026
Institutions Reporting
144
Shares (Excl. Options)
47,961,291
Price
$43.99
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Latest holder context comes from 144 institutions filings for Q2 2026.
Security key
829401108
Latest holder period
Q2 2026
13F holders
144
13D/G owners
8
CIK / CUSIP context first
Broader feeds
Open recent reporting periods for CUSIP 829401108:
13D/G owners
Large-stake holder rows connected to Schedule 13D/G evidence.
| Filer | Ownership | Change % | Holdings Value | Net Change | Nb Shares | Change % | Reporting Name | Report Period |
|---|---|---|---|---|---|---|---|---|
| TPG GP A, LLC | 15% | $80,486,942 | 6,684,962 | TPG GP A, LLC | 10 Feb 2025 | |||
| RA CAPITAL MANAGEMENT, L.P. | 14% | -36% | $38,015,253 | -$21,105,697 | 6,476,193 | -36% | RA Capital Management, L.P. | 17 Sep 2026 |
| VIKING GLOBAL INVESTORS LP | 7.1% | +5.7% | $133,462,710 | +$10,126,176 | 3,195,181 | +8.2% | VIKING GLOBAL INVESTORS LP | 31 Mar 2026 |
| ORBIMED ADVISORS LLC | 6.6% | -22% | $118,970,633 | -$29,554,504 | 2,967,722 | -20% | ORBIMED ADVISORS LLC | 15 Apr 2026 |
| Enavate Sciences GP, LLC | 5.6% | $29,835,481 | 2,478,030 | Enavate Sciences GP, LLC | 10 Feb 2025 | |||
| Atlas Venture Fund XI, L.P. | 5.4% | -16% | $74,744,824 | -$15,805,403 | 2,382,495 | -17% | Atlas Venture Fund XI, L.P. | 16 Oct 2025 |
| Qatar Investment Authority | 4.5% | -10% | $84,386,177 | -$7,916,125 | 2,020,258 | -8.6% | Qatar Investment Authority | 31 Mar 2026 |
| JPMORGAN CHASE & CO | 4.4% | -12% | $58,251,993 | -$7,075,145 | 1,980,626 | -11% | JPMORGAN CHASE & CO. | 30 Sep 2025 |
As of 30 Jun 2026, 144 institutional investors reported holding 47,961,291 shares of Sionna Therapeutics, Inc. - Common Stock, $0.001 par value per share (SION). This represents 106% of the company’s total 45,288,063 outstanding shares.
13F concentration
Largest 13F positions for this security by reported shares and value.
| Institution | Ownership % | Shares Held | Share Change % | Portfolio % | Holdings Value |
|---|---|---|---|---|---|
| RA CAPITAL MANAGEMENT, L.P. | 22% | 9,905,045 | 0% | 3.8% | $435,722,930 |
| TPG GP A, LLC | 14% | 6,494,962 | 0% | 5.7% | $285,713,378 |
| VIKING GLOBAL INVESTORS LP | 7.1% | 3,195,181 | 0% | 0.4% | $140,556,012 |
| Atlas Venture Life Science Advisors, LLC | 6.6% | 2,995,602 | 0% | 15% | $131,776,532 |
| ORBIMED ADVISORS LLC | 5.6% | 2,555,877 | -28% | 2.1% | $112,433,029 |
| ENAVATE SCIENCES GP, LLC | 5.5% | 2,478,030 | 0% | 32% | $109,008,540 |
| ADAGE CAPITAL PARTNERS GP, L.L.C. | 3.5% | 1,600,000 | +967% | 0.1% | $70,384,000 |
| JPMORGAN CHASE & CO | 3.3% | 1,490,508 | +1.7% | 0% | $64,085,673 |
| BlackRock, Inc. | 3.3% | 1,474,769 | +14% | 0% | $64,875,089 |
| JENNISON ASSOCIATES LLC | 2.6% | 1,172,133 | -19% | 0.03% | $51,562,131 |
| CITADEL ADVISORS LLC | 2.5% | 1,147,636 | -1.7% | 0.03% | $50,484,507 |
| VANGUARD CAPITAL MANAGEMENT LLC | 2.5% | 1,132,001 | +10% | 0% | $49,796,724 |
| STATE STREET CORP | 2.3% | 1,021,534 | +35% | 0% | $44,937,281 |
| PERCEPTIVE ADVISORS LLC | 2% | 905,000 | +37% | 0.62% | $39,810,950 |
| DEERFIELD MANAGEMENT COMPANY, L.P. | 1.5% | 680,916 | -30% | 0.31% | $29,953,495 |
| Siren, L.L.C. | 1.3% | 610,515 | +104% | 0.55% | $26,856,555 |
| PRICE T ROWE ASSOCIATES INC /MD/ | 1.1% | 478,016 | -37% | 0% | $21,029,000 |
| EVENTIDE ASSET MANAGEMENT, LLC | 1% | 474,981 | -26% | 0.28% | $20,894,402 |
| GEODE CAPITAL MANAGEMENT, LLC | 1% | 457,145 | +17% | 0% | $20,113,984 |
| Casdin Capital, LLC | 0.88% | 400,000 | 0.88% | $17,596,000 | |
| BAKER BROS. ADVISORS LP | 0.88% | 400,000 | 0% | 0.09% | $17,596,000 |
| GOLDMAN SACHS GROUP INC | 0.86% | 388,810 | +48% | 0% | $17,103,752 |
| Driehaus Capital Management LLC | 0.85% | 385,447 | +403% | 0.1% | $16,955,814 |
| FRANKLIN RESOURCES INC | 0.64% | 290,113 | +65% | 0% | $12,762,071 |
| Aberdeen Group plc | 0.63% | 284,138 | -50% | 0.02% | $12,499,231 |
Quarter history
Holder count, reported shares/value, and median price by quarter.
| Period | 13F Shares, Excl. Options | Value, Excl. Options | Value Change | Price (Median) | Investors |
|---|---|---|---|---|---|
| 2026 Q2 | 47,961,291 | $2,108,229,075 | +$114,782,276 | $43.99 | 144 |
| 2026 Q1 | 45,407,309 | $1,815,366,651 | +$51,789,321 | $40.09 | 121 |
| 2025 Q4 | 43,950,880 | $1,808,143,956 | +$42,254,824 | $41.14 | 101 |
| 2025 Q3 | 42,840,564 | $1,259,943,482 | -$14,718,322 | $29.41 | 78 |
| 2025 Q2 | 43,448,393 | $753,831,077 | +$37,292,994 | $17.35 | 65 |
| 2025 Q1 | 41,491,947 | $434,056,422 | +$434,056,422 | $10.46 | 47 |