SION Institutional Ownership
Who owns Sionna Therapeutics, Inc. and what the big funds did with it last quarter, from every SEC 13F filing. 147 funds reported holding SION at Jun 30, 2026, together owning 106.8% of the company.
- ▲91 buying vs 48 selling
- ▲Held by funds +5.8 pts
- ▲Funds holding +25
- ▼Superinvestors: 1 added, 2 cut
- ●Put/call not meaningful
What the filings show, not a forecast. Positions can be up to 45 days old and leave out short sales.
Funds holding and ownership
6 quartersQuarter over quarter
all 13F filers| Q2 2026 | This quarter | Q1 2026 | Change |
|---|---|---|---|
| Funds holding | 147 | 122 | +20.5% |
| In funds' top 10 | 6 | 8 | −25.0% |
| 13F shares | 48.3M | 45.6M | +5.8% |
| Held by funds | 106.8% | 101.0% | +5.8 pts |
| New positions | 34 | 28 | +21.4% |
| Increased | 57 | 41 | +39.0% |
| Reduced | 40 | 29 | +37.9% |
| Sold out | 8 | 9 | −11.1% |
| Calls (shares) | 25K | 0 | – |
| Puts (shares) | 169K | 0 | – |
| Put/call ratio | 6.74 | – | – |
Buyers vs sellers
adding or new vs cutting or sold outSuperinvestors in SION
All superinvestors →
Who owns SION
share of fund held shares- Index and passive funds9.9%
- Active managers and hedge funds84.5%
- Banks and brokers5.5%
- Pensions, insurers and other0.2%
The top 10 holders own 69.1% of all SION shares that funds reported. Groups are our own grouping of filers by name.
Filed so far for Q3 2026
31 funds changed their position- Y-Intercept (Hong Kong) LtdNew+1.1M sh
- Mutual of America Capital Management LLCSold out−36K sh
- Caitong International Asset Management Co., LtdAdded+89K sh
- Profund Advisors LLCSold out−9,140 sh
- Creative PlanningNew+43K sh
🔒 Free account: see all 20.
Top holders
Q2 2026| # | Fund | Of company | Shares | Value | Change |
|---|---|---|---|---|---|
| 1 | RA Capital Management, L.P. | 21.91% | 9.9M | $436M | 0 |
| 2 | Tpg GP A, LLC | 14.37% | 6.5M | $286M | 0 |
| 3 | Viking Global Investors LP | 7.07% | 3.2M | $141M | 0 |
| 4 | Atlas Venture Life Science Advisors, LLC | 6.63% | 3M | $132M | 0 |
| 5 | Orbimed Advisors LLC | 5.65% | 2.6M | $112M | −975K |
| 6 | Enavate Sciences Gp, LLC | 5.48% | 2.5M | $109M | 0 |
| 7 | Adage Capital Partners Gp, L.l.c. | 3.54% | 1.6M | $70.4M | +1.4M |
| 8 | Jpmorgan Chase & Co | 3.30% | 1.5M | $64.1M | +25K |
| 9 | BlackRock, Inc. | 3.26% | 1.5M | $64.9M | +179K |
| 10 | Jennison Associates LLC | 2.59% | 1.2M | $51.6M | −279K |
- Adage Capital Partners Gp, L.l.c.+1.4M sh+$63.8M
- Casdin Capital, LLC+400K sh+$17.6M
- Siren, L.L.C.+311K sh+$13.7M
- Driehaus Capital Management LLC+309K sh+$13.6M
- State Street Corp+265K sh+$11.7M
- Perceptive Advisors LLC+247K sh+$10.8M
- Fmr LLC+197K sh+$8.7M
- Artisan Partners Limited Partnership+189K sh+$8.3M
- Orbimed Advisors LLC−975K sh−$42.9M
- Deerfield Management Company, L.P.−290K sh−$12.7M
- Aberdeen Group plc−280K sh−$12.3M
- Jennison Associates LLC−279K sh−$12.3M
- Price T Rowe Associates Inc /md/−278K sh−$12.2M
- Eventide Asset Management, LLC−171K sh−$7.5M
- Sio Capital Management, LLC−167K sh−$7.3M
- Soleus Capital Management, L.P.−116K sh−$5.1M
SION institutional ownership FAQ
Who owns the most SION stock?
In Q2 2026 13F filings the largest holder of SION was RA Capital Management, L.P., followed by Tpg GP A, LLC and Viking Global Investors LP. Index fund managers are usually the biggest holders of large companies.
What percentage of SION is owned by institutions?
Funds that file 13F reports held 106.8% of SION's shares at Jun 30, 2026, compared with 101.0% a quarter earlier. That counts every manager with more than $100 million in US stocks.
Are hedge funds buying SION?
In Q2 2026, 91 funds bought SION (34 of them new positions) and 48 sold (8 sold out completely). Among well known investors, 1 added and 2 cut. Our fund sentiment for SION is bullish.
What is SION's institutional put/call ratio?
Funds reported $7.4M of SION puts against $1.1M of calls, a put/call ratio of 6.74. Market makers and bank trading desks are left out, since their options are mostly hedges.
How current is this SION ownership data?
13F filings show holdings at the end of each quarter and are due within 45 days, so positions can be up to six weeks old when they appear. We add each new filing within minutes, and the "filed so far" list shows funds that have already reported the next quarter.
For informational and educational purposes only. Not investment advice, and not a recommendation to buy or sell any security. Fund sentiment summarises what 13F filings show and is not a forecast. Holdings come from SEC Form 13F filings as reported and show positions at the end of the quarter, up to 45 days before the filing. A 13F leaves out short positions, cash, bonds and most foreign holdings. See all hedge fund holdings.