SION Institutional Ownership & Shareholders
SIONNA THERAPEUTICS INC (SION) is currently held by 149 institutional investors tracked by InsiderSet, with a combined reported market value of approximately $2.09B based on the latest available SEC Form 13F filings for the quarter ended June 30, 2026.
Ra Capital Management, L.P. is currently the largest disclosed institutional shareholder of SION tracked by InsiderSet, reporting ownership valued at approximately $435.72M in its June 30, 2026 SEC Form 13F filing. Based on current market prices and the latest disclosed share count, the position is now estimated to be worth approximately $36.95M, representing an estimated loss of -91.52% since the filing period.
The top 10 institutional shareholders tracked on this page collectively account for approximately 70% of the total disclosed SION value among the investors covered in this analysis. Major shareholders include Ra Capital Management, L.P., Tpg Gp A, Llc, Viking Global Investors, and several other long-term asset managers with concentrated positions in SIONNA THERAPEUTICS INC (SION).
This page ranks the largest institutional SION shareholders using publicly disclosed SEC Form 13F data, including reported values, estimated current holding values, portfolio allocation percentages, ownership concentration metrics, and historical holding changes across major hedge funds and investment firms.
Institutional Holders
149
Total Reported Value
$2.09B
Largest Holder
Ra Capital Management, L.P.
Largest Position
$435.72M
Insider Transactions (90d)
6
Latest Filing Quarter
Q2 2026
New Institutional Positions
126
Funds Exiting Positions
0
| Name | Investor/Manager | Portfolio % | Quantity | Reported Balance | Current Estimated Value | Gain/loss Since Filing | Estimated Portfolio Performance |
|---|---|---|---|---|---|---|---|
| Ra Capital Management, L.P. | 3.79% | 9,905,045 | $435,722,930 | $36,945,818 | -$398,777,112 | -91.52% | |
| Tpg Gp A, Llc | 5.71% | 6,494,962 | $285,713,378 | $24,226,208 | -$261,487,170 | -91.52% | |
| Viking Global Investors | Ole Andreas Halvorsen | 0.40% | 3,195,181 | $140,556,012 | $11,918,025 | -$128,637,987 | -91.52% |
| Atlas Venture Life Science Advisors, Llc | 14.95% | 2,995,602 | $131,776,532 | $11,173,595 | -$120,602,937 | -91.52% | |
| Orbimed Advisors Llc | 2.13% | 2,555,877 | $112,433,029 | $9,533,421 | -$102,899,608 | -91.52% | |
| Enavate Sciences Gp, Llc | 31.56% | 2,478,030 | $109,008,540 | $9,243,052 | -$99,765,488 | -91.52% | |
| Adage Capital Partners Gp, L.L.C. | 0.10% | 1,600,000 | $70,384,000 | $5,968,000 | -$64,416,000 | -91.52% | |
| Blackrock, Inc. | 0.00% | 1,474,769 | $64,875,089 | $5,500,888 | -$59,374,201 | -91.52% | |
| Jpmorgan Chase & Co | 0.00% | 1,490,508 | $64,085,673 | $5,559,595 | -$58,526,078 | -91.32% | |
| Jennison Associates Llc | 0.03% | 1,172,133 | $51,562,131 | $4,372,056 | -$47,190,075 | -91.52% | |
| Citadel Advisors Llc | 0.03% | 1,147,636 | $50,484,507 | $4,280,682 | -$46,203,825 | -91.52% | |
| Vanguard Capital Management Llc | 0.00% | 1,132,001 | $49,796,724 | $4,222,364 | -$45,574,360 | -91.52% | |
| State Street Corp | 0.00% | 1,021,534 | $44,937,281 | $3,810,322 | -$41,126,959 | -91.52% | |
| Perceptive Advisors Llc | 0.62% | 905,000 | $39,810,950 | $3,375,650 | -$36,435,300 | -91.52% | |
| Deerfield Management Company, L.P. | 0.31% | 680,916 | $29,953,495 | $2,539,817 | -$27,413,678 | -91.52% | |
| Siren, L.L.C. | 0.55% | 610,515 | $26,856,555 | $2,277,221 | -$24,579,334 | -91.52% | |
| Price T Rowe Associates Inc | 0.00% | 478,016 | $21,029,000 | $1,783,000 | -$19,246,000 | -91.52% | |
| Eventide Asset Management, Llc | 0.28% | 474,981 | $20,894,402 | $1,771,679 | -$19,122,723 | -91.52% | |
| Geode Capital Management, Llc | 0.00% | 457,145 | $20,113,984 | $1,705,151 | -$18,408,833 | -91.52% | |
| Baker Bros. Advisors Lp | 0.09% | 400,000 | $17,596,000 | $1,492,000 | -$16,104,000 | -91.52% | |
| Casdin Capital, Llc | 0.88% | 400,000 | $17,596,000 | $1,492,000 | -$16,104,000 | -91.52% | |
| Goldman Sachs Group Inc | 0.00% | 388,810 | $17,103,752 | $1,450,261 | -$15,653,491 | -91.52% | |
| Driehaus Capital Management Llc | 0.10% | 385,447 | $16,955,814 | $1,437,717 | -$15,518,097 | -91.52% | |
| Aberdeen Group Plc | 0.02% | 284,138 | $12,499,231 | $1,059,835 | -$11,439,396 | -91.52% | |
| Fmr Llc | 0.00% | 278,292 | $12,242,065 | $1,038,029 | -$11,204,036 | -91.52% | |
| Millennium Management Llc | 0.01% | 276,733 | $12,173,485 | $1,032,214 | -$11,141,271 | -91.52% | |
| Ensign Peak Advisors, Inc | 0.02% | 255,636 | $10,248,447 | $953,522 | -$9,294,925 | -90.70% | |
| Vanguard Portfolio Management Llc | 0.00% | 222,949 | $9,807,527 | $831,600 | -$8,975,927 | -91.52% | |
| Kalehua Capital Management Llc | 4.98% | 197,072 | $8,669,197 | $735,079 | -$7,934,118 | -91.52% | |
| Longaeva Partners L.P. | 0.25% | 196,352 | $8,637,524 | $732,393 | -$7,905,131 | -91.52% | |
| Artisan Partners Limited Partnership | 0.01% | 189,498 | $8,336,017 | $706,828 | -$7,629,189 | -91.52% | |
| Soleus Capital Management, L.P. | 0.27% | 177,687 | $7,816,451 | $662,773 | -$7,153,678 | -91.52% | |
| Northern Trust Corp | 0.00% | 154,476 | $6,795,399 | $576,195 | -$6,219,204 | -91.52% | |
| Morgan Stanley | 0.00% | 151,047 | $6,644,558 | $563,405 | -$6,081,153 | -91.52% | |
| Sofinnova Investments, Inc. | 0.34% | 144,432 | $6,353,564 | $538,731 | -$5,814,833 | -91.52% | |
| Qube Research & Technologies Ltd | 0.01% | 140,309 | $6,172,193 | $523,353 | -$5,648,840 | -91.52% | |
| Alyeska Investment Group, L.P. | 0.02% | 136,222 | $5,992,406 | $508,108 | -$5,484,298 | -91.52% | |
| Gordonmd Global Investments Lp | 2.89% | 136,000 | $5,982,640 | $507,280 | -$5,475,360 | -91.52% | |
| Charles Schwab Investment Management Inc | 0.00% | 129,753 | $5,707,834 | $483,979 | -$5,223,855 | -91.52% | |
| Sio Capital Management, Llc | 0.96% | 127,808 | $5,622,274 | $476,724 | -$5,145,550 | -91.52% | |
| Y-Intercept (Hong Kong) Ltd | 0.12% | 1,056,885 | $5,559,215 | $3,942,181 | -$1,617,034 | -29.09% | |
| Vanguard Fiduciary Trust Co | 0.00% | 121,442 | $5,342,234 | $452,979 | -$4,889,255 | -91.52% | |
| Artia Global Partners Lp | 1.00% | 119,741 | $5,267,407 | $446,634 | -$4,820,773 | -91.52% | |
| Ubs Group Ag | 0.00% | 116,206 | $5,111,902 | $433,448 | -$4,678,454 | -91.52% | |
| First Turn Management, Llc | 0.52% | 110,493 | $4,860,587 | $412,139 | -$4,448,448 | -91.52% | |
| Citigroup Inc | 0.00% | 110,163 | $4,846,070 | $410,908 | -$4,435,162 | -91.52% | |
| D. E. Shaw & Co., Inc. | 0.00% | 101,644 | $4,471,320 | $379,132 | -$4,092,188 | -91.52% | |
| Rock Springs Capital Management Lp | 0.21% | 99,429 | $4,373,882 | $370,870 | -$4,003,012 | -91.52% | |
| Walleye Capital Llc | 0.02% | 97,347 | $4,282,295 | $363,104 | -$3,919,191 | -91.52% | |
| Rhenman & Partners Asset Management Ab | 0.40% | 97,100 | $4,271,429 | $362,183 | -$3,909,246 | -91.52% |
Frequently asked questions about SION
Who are the largest institutional holders of SION?
The largest institutional holders of SION reported in the latest SEC Form 13F filings include Ra Capital Management, L.P., Tpg Gp A, Llc, Viking Global Investors, Atlas Venture Life Science Advisors, Llc, and Orbimed Advisors Llc. InsiderSet ranks institutional holders by their latest reported SION position.
What is SION institutional ownership?
This page tracks SION positions reported by institutional investment managers through SEC Form 13F. SIONNA THERAPEUTICS INC (SION) institutional ownership on InsiderSet reflects disclosed 13F holdings among the managers we analyze, not every shareholder of the stock.
How many institutions own SION?
InsiderSet currently tracks 149 institutional managers reporting SION holdings in the latest available 13F data. This count reflects institutions included in the SEC Form 13F filings analyzed by InsiderSet and should not be interpreted as the total number of SION shareholders.
How much SION stock do institutions own?
Institutional investment managers disclosed approximately $2.09B in SION holdings for Q2 2026. This figure is reported 13F value as of the filing period, not necessarily today's market value.
When was SION institutional ownership last updated?
The latest SION institutional ownership data on InsiderSet is based on SEC Form 13F filings for the quarter ended June 30, 2026. Form 13F filings are generally reported after the quarter ends, so the holdings shown represent the latest publicly disclosed positions rather than real-time institutional holdings.
Are institutional SION holdings real-time?
No. Form 13F data is not real-time. It represents positions reported by institutional investment managers as of the end of the reporting quarter. An institution may have changed its SION position after the reporting date.
Are institutions buying or selling SION?
Institutional buying and selling can be analyzed by comparing SION positions across consecutive 13F reporting periods. InsiderSet's SION Ownership Changes page shows institutions that increased, reduced, initiated, or exited positions based on reported 13F holdings. View SION ownership changes.
How has SION institutional ownership changed over time?
InsiderSet tracks SION institutional holdings across multiple 13F reporting periods, allowing investors to compare institutional holder counts, reported value, and reported shares over time.