Michael Cloonan - Oct 21, 2025 Form 4 Insider Report for Sionna Therapeutics, Inc. (SION)

Role
President & CEO, Director
Signature
Jennifer Fitzpatrick, Attorney-in-Fact
Stock symbol
SION
Transactions as of
Oct 21, 2025
Transactions value $
-$3,008,782
Form type
4
Date filed
10/22/2025, 05:39 PM
Previous filing
Oct 17, 2025
SEC
View on sec.gov

Reporting Owners (1)

Name Relationship Address Signature Signature date CIK
Cloonan Michael President & CEO, Director C/O SIONNA THERAPEUTICS, INC., 21 HICKORY DRIVE, SUITE 500, WALTHAM Jennifer Fitzpatrick, Attorney-in-Fact 2025-10-22 0001704336

Transactions Table

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Ownership Footnotes
transaction SION Common Stock Options Exercise $81.4K +13.3K +2.43% $6.11 561K Oct 21, 2025 Direct F1
transaction SION Common Stock Sale -$459K -13.3K -2.38% $34.44 547K Oct 21, 2025 Direct F1, F2
transaction SION Common Stock Options Exercise $184K +30K +5.49% $6.11 577K Oct 21, 2025 Direct F1
transaction SION Common Stock Sale -$1.07M -30K -5.2% $35.63 547K Oct 21, 2025 Direct F1, F3
transaction SION Common Stock Options Exercise $140K +22.9K +4.18% $6.11 570K Oct 21, 2025 Direct F1
transaction SION Common Stock Sale -$838K -22.9K -4.01% $36.60 547K Oct 21, 2025 Direct F1, F4
transaction SION Common Stock Options Exercise $205K +33.5K +6.13% $6.11 581K Oct 21, 2025 Direct F1
transaction SION Common Stock Sale -$1.25M -33.5K -5.77% $37.31 547K Oct 21, 2025 Direct F1, F5

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Underlying Class Amount Exercise Price Ownership Footnotes
transaction SION Non-Qualified Stock Option (right to buy) Options Exercise $0 -13.3K -8.71% $0.00 140K Oct 21, 2025 Common Stock 13.3K $6.11 Direct F1, F6
transaction SION Non-Qualified Stock Option (right to buy) Options Exercise $0 -30K -21.52% $0.00 110K Oct 21, 2025 Common Stock 30K $6.11 Direct F1, F6
transaction SION Non-Qualified Stock Option (right to buy) Options Exercise $0 -22.9K -20.9% $0.00 86.7K Oct 21, 2025 Common Stock 22.9K $6.11 Direct F1, F6
transaction SION Non-Qualified Stock Option (right to buy) Options Exercise $0 -33.5K -38.69% $0.00 53.1K Oct 21, 2025 Common Stock 33.5K $6.11 Direct F1, F6
* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Buy Plan / Sale Plan: These are also open market purchases/sales of shares, but in this case the transaction is part of a trading plan. Rule 10b5-1 allows insiders to setup a trading plan to buy/sell stocks over a certain period of time. Since the purchases/sales are predetermined, this protects the insiders from violating insider trading law.

Transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c).

Explanation of Responses:

Id Content
F1 This transaction was automatically executed pursuant to a Rule 10b5-1 trading plan adopted on May 21, 2025.
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.
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.
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.
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.
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.