Key facts
- This page summarizes Michael Cloonan's Form 4 filing for Sionna Therapeutics, Inc. (SION).
- 12 reported transactions and 4 derivative rows are listed below.
- Accepted by SEC: 22 Oct 2025, 17:39.
Michael Cloonan - 21 Oct 2025 Form 4 Insider Report for Sionna Therapeutics, Inc. (SION)
- Reporting relationship
- President & CEO, Director
- Issuer ticker
- SION
- Reported as of
- 21 Oct 2025
- Net transaction value
- -$3,008,782
- SEC form
- 4
- Accepted by SEC
- 22 Oct 2025, 17:39:46 UTC
- Prior SEC filing
- 17 Oct 2025
- Next SEC filing
- 06 Jan 2026
- Source filing
- View source filing
- Reporting owner signature
- Jennifer Fitzpatrick, Attorney-in-Fact
Source evidence
Original filing metadata and source links for verification.
5 source fields
Reporting owner
1 detail
Key filing fact
Michael Cloonan filed Form 4 for Sionna Therapeutics, Inc. (SION) on 22 Oct 2025.
Change
- Previous filing in this sequence was filed on 17 Oct 2025.
- Current net transaction value: -$3,008,782.
Research use
- This tells you what this filing adds before you inspect full transaction and derivative tables.
- You can trace every row back to the original SEC filing document.
Evidence
Filed on Form 4
View source filing
Ownership activity is grounded in SEC Form 4 disclosures.
Reporting Owners (1)
CIK 0001704336
Primary reporting owner
Cloonan Michael
- Relationship
- President & CEO, Director
- Address
- C/O SIONNA THERAPEUTICS, INC., 21 HICKORY DRIVE, SUITE 500, WALTHAM
- Signature
- Jennifer Fitzpatrick, Attorney-in-Fact
- Signature date
- 22 Oct 2025
Reported non-derivative transactions
Shares, units, or other non-derivative securities reported in this filing.
SION
transaction
Common Stock
Options Exercise
- Transaction value
- $81,410
- Shares
- +13,324
- Change %
- +2.4%
- Price
- $6.11
- Shares after
- 560,667
- Date
- 21 Oct 2025
- Ownership
- Direct
- Footnotes
- F1
SION
transaction
Common Stock
Sale
- Transaction value
- $458,879
- Shares
- -13,324
- Change %
- -2.4%
- Price
- $34.44
- Shares after
- 547,343
- Date
- 21 Oct 2025
- Ownership
- Direct
- Footnotes
- F1, F2
SION
transaction
Common Stock
Options Exercise
- Transaction value
- $183,599
- Shares
- +30,049
- Change %
- +5.5%
- Price
- $6.11
- Shares after
- 577,392
- Date
- 21 Oct 2025
- Ownership
- Direct
- Footnotes
- F1
SION
transaction
Common Stock
Sale
- Transaction value
- $1,070,646
- Shares
- -30,049
- Change %
- -5.2%
- Price
- $35.63
- Shares after
- 547,343
- Date
- 21 Oct 2025
- Ownership
- Direct
- Footnotes
- F1, F3
SION
transaction
Common Stock
Options Exercise
- Transaction value
- $139,888
- Shares
- +22,895
- Change %
- +4.2%
- Price
- $6.11
- Shares after
- 570,238
- Date
- 21 Oct 2025
- Ownership
- Direct
- Footnotes
- F1
SION
transaction
Common Stock
Sale
- Transaction value
- $837,957
- Shares
- -22,895
- Change %
- -4%
- Price
- $36.60
- Shares after
- 547,343
- Date
- 21 Oct 2025
- Ownership
- Direct
- Footnotes
- F1, F4
SION
transaction
Common Stock
Options Exercise
- Transaction value
- $204,881
- Shares
- +33,532
- Change %
- +6.1%
- Price
- $6.11
- Shares after
- 580,875
- Date
- 21 Oct 2025
- Ownership
- Direct
- Footnotes
- F1
SION
transaction
Common Stock
Sale
- Transaction value
- $1,251,079
- Shares
- -33,532
- Change %
- -5.8%
- Price
- $37.31
- Shares after
- 547,343
- Date
- 21 Oct 2025
- Ownership
- Direct
- Footnotes
- F1, F5
Reported derivative securities
Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.
SION
transaction
Derivative
Non-Qualified Stock Option (right to buy)
Options Exercise
- Transaction value
- $0
- Shares
- -13,324
- Change %
- -8.7%
- Price
- $0.000000
- Shares after
- 139,618
- Date
- 21 Oct 2025
- Ownership
- Direct
- Underlying class
- Common Stock
- Underlying amount
- 13,324
- Exercise price
- $6.11
- Footnotes
- F1, F6
SION
transaction
Derivative
Non-Qualified Stock Option (right to buy)
Options Exercise
- Transaction value
- $0
- Shares
- -30,049
- Change %
- -22%
- Price
- $0.000000
- Shares after
- 109,569
- Date
- 21 Oct 2025
- Ownership
- Direct
- Underlying class
- Common Stock
- Underlying amount
- 30,049
- Exercise price
- $6.11
- Footnotes
- F1, F6
SION
transaction
Derivative
Non-Qualified Stock Option (right to buy)
Options Exercise
- Transaction value
- $0
- Shares
- -22,895
- Change %
- -21%
- Price
- $0.000000
- Shares after
- 86,674
- Date
- 21 Oct 2025
- Ownership
- Direct
- Underlying class
- Common Stock
- Underlying amount
- 22,895
- Exercise price
- $6.11
- Footnotes
- F1, F6
SION
transaction
Derivative
Non-Qualified Stock Option (right to buy)
Options Exercise
- Transaction value
- $0
- Shares
- -33,532
- Change %
- -39%
- Price
- $0.000000
- Shares after
- 53,142
- Date
- 21 Oct 2025
- Ownership
- Direct
- Underlying class
- Common Stock
- Underlying amount
- 33,532
- Exercise price
- $6.11
- Footnotes
- F1, F6
* marks a reported price that did not pass the local price check.
Additional SEC filing notes
Filing notes and footnotes
Rule 10b5-1 trading plan
These transactions were reported as open-market trades under a Rule 10b5-1 plan. The plan lets an insider set trading instructions in advance, which can reduce the risk of trading while in possession of material nonpublic information.
Original filing language: transaction made pursuant to a contract, instruction, or written plan intended to satisfy Rule 10b5-1(c).
Explanation of responses 6 footnotes
Footnote F1
This transaction was automatically executed pursuant to a Rule 10b5-1 trading plan adopted on May 21, 2025.
Footnote F2
The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $34.00 to $34.95, inclusive. The Reporting Person undertakes to provide to the Issuer, any securityholder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price at which the transactions were effected.
Footnote F3
The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $35.00 to $35.99, inclusive. The Reporting Person undertakes to provide to the Issuer, any securityholder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price at which the transactions were effected.
Footnote F4
The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $36.00 to $36.99, inclusive. The Reporting Person undertakes to provide to the Issuer, any securityholder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price at which the transactions were effected.
Footnote F5
The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $37.00 to $37.80, inclusive. The Reporting Person undertakes to provide to the Issuer, any securityholder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price at which the transactions were effected.
Footnote F6
The shares underlying this option vest in forty-eight equal monthly installments following February 2, 2022, subject to the Reporting Person's continued service on each such vesting date.