SION on Nasdaq

Sionna Therapeutics, Inc.

American pharmaceutical preparations company, incorporated in Delaware. Summary from the record

Price unavailable

Last updated Oct 19, 2026.

Overview

Compare with another stock.

  • TickerSION on Nasdaq1
  • IndustryPharmaceutical Preparations1
  • HeadquartersWaltham, Massachusetts1
  • Incorporated inDE2
  • Business address21 Hickory Drive, Suite 500, Waltham, Ma 024512
  • Filer category, Emerging growth company2

See how the biggest companies compare on our leaderboards

We are a clinical-stage biopharmaceutical company on a mission to revolutionize the current treatment paradigm for cystic fibrosis (“CF”) by developing novel medicines that normalize the function of the cystic fibrosis transmembrane conductance regulator (“CFTR”) protein to deliver clinically meaningful benefit to people with CF. CF is a progressive and life-threatening genetic disease caused by inherited mutations in the CFTR gene, which lead to insufficient CFTR function. While advances in the discovery and development of CFTR modulators have significantly improved the lives of people with CF, at least two-thirds of patients on the current standard of care do not have normal CFTR function, defined as sweat chloride levels below 30 mmol/L. Patients with reduced CFTR function can experience debilitating multi-system complications that lead to significantly impaired quality of life and sh…3 From its latest annual report

Financials

From the company’s reports to the SEC. Every number links to the filing it came from.

Financial statements

Operating income4-$89.0M in 2025+26% since 2024
-$100.0M-$75.0M-$50.0M-$25.0M02024: -$70.6M-$70.6M20242025: -$89.0M-$89.0M2025+26%
Net income4-$75.3M in 2025+22% since 2024
-$80.0M-$60.0M-$40.0M-$20.0M02024: -$61.7M-$61.7M20242025: -$75.3M-$75.3M2025+22%

Every line of the income statement as filed: the last 2 fiscal years, latest first.4

Period ending2025-12-312024-12-31
Research and development$60.3M$57.3M
General and administrative$28.7M$13.3M
Total operating expenses$89.0M$70.6M
Loss from operations-$89.0M-$70.6M
Interest income$13.3M$8.2M
Other income$419.0K$698.0K
Total other income$13.7M$8.9M
Net loss-$75.3M-$61.7M
Net loss per share, basic (in dollars per share)-$1.88-$15.99
Net loss per share, diluted (in dollars per share)-$1.88-$15.99
Weighted-average common shares outstanding, basic (in shares)40.0M shares3.9M shares
Weighted-average common shares outstanding, diluted (in shares)40.0M shares3.9M shares
Unrealized gain on marketable securities$172.0K$368.0K
Total other comprehensive gain$172.0K$368.0K
Comprehensive loss-$75.1M-$61.3M

Compare Sionna Therapeutics, Inc. with another company

Leadership

Who has led Sionna Therapeutics, Inc., and when. Pick a name to see everywhere that person has worked.

Chief executive

  1. Michael Cloonan2025–now

President

  1. Michael Cloonan2025–now

Chief financial officer

  1. Elena Ridloff2025–now
Board members and other officers (14)

Timeline

  1. Feb 6, 2025New chief executive Michael Cloonan becomes CEO7

Filings

231 filings to the SEC since October 2021: 2 annual reports, 5 quarterly reports, 13 major events, 100 insider forms, 15 large holders, 96 other. The latest 20:

  1. Sep 21, 2026SCHEDULE 13D/A EDGAR
  2. Sep 21, 20264 EDGAR
  3. Sep 18, 20264 PRIMARY DOCUMENT EDGAR
  4. Sep 18, 20264 PRIMARY DOCUMENT EDGAR
  5. Sep 18, 20264 PRIMARY DOCUMENT EDGAR
  6. Sep 18, 20264 PRIMARY DOCUMENT EDGAR
  7. Sep 17, 2026144 EDGAR
  8. Sep 14, 20268-K EDGAR
  9. Aug 10, 20268-K EDGAR
  10. Aug 6, 202610-Q EDGAR
  11. Aug 6, 20268-K EDGAR
  12. Jul 9, 20264 EDGAR
  13. Jul 9, 20264 EDGAR
  14. Jul 7, 20264 PRIMARY DOCUMENT EDGAR
  15. Jul 6, 2026144 EDGAR
  16. Jul 2, 20264 EDGAR
  17. Jul 2, 20264 EDGAR
  18. Jun 18, 20264 PRIMARY DOCUMENT EDGAR
  19. Jun 18, 20264 PRIMARY DOCUMENT EDGAR
  20. Jun 18, 20264 PRIMARY DOCUMENT EDGAR

The 231 filings since October 2021 can be filtered by form type and year here when JavaScript is on.

Every filing from the last five years, summarized. The full record is on SEC EDGAR.

Insider trades

88 open-market trades by officers, directors and large owners since October 2021: 7 buys and 81 sales. Grants, option exercises and gifts are left out.

DateWhoTradeSharesPriceValueFiling
Sep 17, 2026RA CAPITAL MANAGEMENT, L.P.DirectorSale3,448,811$6.33$21.8MForm 4
Jul 7, 2026Thompson Peter A.DirectorSale85,918$44.86$3.9MForm 4
Jul 7, 2026OrbiMed Capital GP VIII LLCDirectorSale85,918$44.86$3.9MForm 4
Jul 6, 2026Fitzpatrick JenniferCLO and Head of Program Mgmt.Sale10,250$43.60$446.9KForm 4
Jun 30, 2026Thompson Peter A.DirectorSale115,844$45.50$5.3MForm 4
Jun 30, 2026ORBIMED ADVISORS LLCDirectorSale115,844$45.50$5.3MForm 4
May 27, 2026Thompson Peter A.DirectorSale101$44.49$4.5KForm 4
May 27, 2026ORBIMED ADVISORS LLCDirectorSale101$44.49$4.5KForm 4
May 11, 2026Thompson Peter A.DirectorSale184,639$46.22$8.5MForm 4
May 11, 2026ORBIMED ADVISORS LLCDirectorSale184,639$46.22$8.5MForm 4
May 8, 2026Thompson Peter A.DirectorSale59,767$44.58$2.7MForm 4
May 8, 2026ORBIMED ADVISORS LLCDirectorSale59,767$44.58$2.7MForm 4
May 7, 2026Thompson Peter A.DirectorSale48,546$44.61$2.2MForm 4
May 7, 2026ORBIMED ADVISORS LLCDirectorSale48,546$44.61$2.2MForm 4
Apr 18, 2026Thompson Peter A.DirectorSale2,948$44.52$131.2KForm 4
Apr 18, 2026ORBIMED ADVISORS LLCDirectorSale2,948$44.52$131.2KForm 4
Apr 17, 2026Thompson Peter A.DirectorSale52,397$44.68$2.3MForm 4
Apr 17, 2026ORBIMED ADVISORS LLCDirectorSale52,397$44.68$2.3MForm 4
Apr 16, 2026Thompson Peter A.DirectorSale226,906$45.34$10.3MForm 4
Apr 16, 2026ORBIMED ADVISORS LLCDirectorSale226,906$45.34$10.3MForm 4

All 88 trades can be filtered by person here when JavaScript is on.

From Forms 4 filed with the SEC.

Major holders

Investors who own more than 5% of the shares must tell the SEC: a 13D if they may seek to influence the company, a 13G if they hold passively.

Held by these funds

The largest holders among investment managers' 13F reports for the quarter ending Jun 30, 2026, the top 25 of 100. Change is in shares since the quarter before.

FundSharesValueShare of the fundChange
Ra Capital Management, L.P.9,905,045$435.7M3.8%No change
Tpg Gp A, LLC6,494,962$285.7M5.7%No change
Viking Global Investors LP3,195,181$140.6M0.4%No change
Atlas Venture Life Science Advisors, LLC2,995,602$131.8M15.0%No change
Orbimed Advisors LLC2,555,877$112.4M2.1%−974,825
Enavate Sciences Gp, LLC2,478,030$109.0M31.6%No change
Adage Capital Partners Gp, L.l.c.1,600,000$70.4M0.1%+1,450,000
BlackRock, Inc.1,474,769$64.9M0.0%+178,902
Jpmorgan Chase & Co1,490,508$64.1M0.0%+25,494
Jennison Associates LLC1,172,133$51.6M0.0%−279,087
Citadel Advisors LLC1,147,636$50.5M0.0%−19,295
Vanguard Capital Management LLC1,132,001$49.8M0.0%+102,504
State Street Corp1,021,534$44.9M0.0%+265,307
Perceptive Advisors LLC905,000$39.8M0.6%+246,561
Deerfield Management Company, L.P.680,916$30.0M0.4%−289,674
Siren, L.L.C.610,515$26.9M0.5%+310,515
Eventide Asset Management, LLC474,981$20.9M0.3%−170,549
Geode Capital Management, LLC457,145$20.1M0.0%+67,273
Baker Bros. Advisors LP400,000$17.6M0.1%No change
Casdin Capital, LLC400,000$17.6M0.9%New
Kalehua Capital Management LLC394,144$17.3M5.5%No change
Goldman Sachs Group Inc388,810$17.1M0.0%+125,636
Driehaus Capital Management LLC385,447$17.0M0.1%+308,814
Franklin Resources Inc290,113$12.8M0.0%+114,630
Aberdeen Group plc284,138$12.5M0.0%−280,037

13F reports cover disclosed long positions in U.S. stocks only.

Sources

The numbers on this page point here. Each one links to the record it came from.

  1. 1
  2. 2
  3. 3
  4. 4
  5. 5
  6. 6
  7. 7
  8. 8
  9. 9
  10. 10
  11. 11
  12. 12
  13. 13
  14. 14
  15. 15
  16. 16
  17. 17
  18. 18
  19. 19
  20. 20
  21. 21
  22. 22
  23. 23
  24. 24
  25. 25
  26. 26
  27. 27
  28. 28