Bruce Booth - 10 Feb 2025 Form 4 Insider Report for Sionna Therapeutics, Inc. (SION)

Reporting relationship: Director
Issuer ticker: SION
Reported as of: 10 Feb 2025
Net transaction value: +$1,080,000
SEC form: 4
Accepted by SEC: 10 Feb 2025, 16:05:05 UTC
Prior SEC filing: 06 Feb 2025
Next SEC filing: 04 Mar 2025
Source filing: View source filing
Reporting owner signature: /s/ Ommer Chohan, Attorney-in-Fact

Key filing fact

Bruce Booth filed Form 4 for Sionna Therapeutics, Inc. (SION) on 10 Feb 2025.

Key facts

This page summarizes Bruce Booth's Form 4 filing for Sionna Therapeutics, Inc. (SION).
8 reported transactions and 5 derivative rows are listed below.
Accepted by SEC: 10 Feb 2025, 16:05.

Change

Previous filing in this sequence was filed on 06 Feb 2025.
Current net transaction value: +$1,080,000.

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

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

SION transaction

Common Stock

Conversion of derivative security

Transaction value
Shares: +2,886,293
Change %
Price
Shares after: 2,886,293
Date: 10 Feb 2025
Ownership: By Atlas Venture Fund XI, L.P.
Footnotes: F1, F2

SION transaction

Common Stock

Conversion of derivative security

Transaction value
Shares: +747,727
Change %
Price
Shares after: 747,727
Date: 10 Feb 2025
Ownership: By Atlas Venture Opportunity Fund II, L.P.
Footnotes: F1, F3

SION transaction

Common Stock

Purchase

Transaction value: $1,080,000
Shares: +60,000
Change %: +8%
Price: $18.00
Shares after: 807,727
Date: 10 Feb 2025
Ownership: By Atlas Venture Opportunity Fund II, L.P.
Footnotes: F3

Reported derivative securities

Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.

SION transaction Derivative

Series Seed convertible preferred stock

Conversion of derivative security

Transaction value: $0
Shares: -1,051,051
Change %: -100%
Price: $0.000000
Shares after: 0
Date: 10 Feb 2025
Ownership: By Atlas Venture Fund XI, L.P.
Underlying class: Common Stock
Underlying amount: 719,355
Exercise price
Footnotes: F1, F2

SION transaction Derivative

Series A convertible preferred stock

Conversion of derivative security

Transaction value: $0
Shares: -1,806,317
Change %: -100%
Price: $0.000000
Shares after: 0
Date: 10 Feb 2025
Ownership: By Atlas Venture Fund XI, L.P.
Underlying class: Common Stock
Underlying amount: 1,236,271
Exercise price
Footnotes: F1, F2

SION transaction Derivative

Series B convertible preferred stock

Conversion of derivative security

Transaction value: $0
Shares: -1,298,332
Change %: -100%
Price: $0.000000
Shares after: 0
Date: 10 Feb 2025
Ownership: By Atlas Venture Fund XI, L.P.
Underlying class: Common Stock
Underlying amount: 888,599
Exercise price
Footnotes: F1, F2

SION transaction Derivative

Series C convertible preferred stock

Conversion of derivative security

Transaction value: $0
Shares: -61,463
Change %: -100%
Price: $0.000000
Shares after: 0
Date: 10 Feb 2025
Ownership: By Atlas Venture Fund XI, L.P.
Underlying class: Common Stock
Underlying amount: 42,068
Exercise price
Footnotes: F1, F2

SION transaction Derivative

Series C convertible preferred stock

Conversion of derivative security

Transaction value: $0
Shares: -1,092,504
Change %: -100%
Price: $0.000000
Shares after: 0
Date: 10 Feb 2025
Ownership: By Atlas Venture Opportunity Fund II, L.P.
Underlying class: Common Stock
Underlying amount: 747,727
Exercise price
Footnotes: F1, F3

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 3 footnotes

Footnote F1

Each share of Series Seed convertible preferred stock, Series A convertible preferred stock, Series B convertible preferred stock and Series C convertible preferred stock (collectively, the "Preferred Stock") automatically converted into shares of the Issuer's Common Stock on a one-for-1.4611 basis upon the closing of the Issuer's initial public offering on February 10, 2025. The Preferred Stock had no expiration date.

Footnote F2

These shares are held directly by Atlas Venture Fund XI, L.P. ("AVF XI "). The general partner of AVF XI is Atlas Venture Associates XI, L.P. ("AVA XI LP"). Atlas Venture Associates XI, LLC ("AVA XI LLC") is the general partner of AVA XI LP. The Reporting Person is a member of AVA XI LLC and disclaims beneficial ownership of such securities held by AVF XI, except to the extent of his pecuniary interest therein, if any.

Footnote F3

These shares are held directly by Atlas Venture Opportunity Fund II, L.P. ("AVOF II"). The general partner of AVOF II is Atlas Venture Associates Opportunity II, L.P. ("AVAO II LP"). Atlas Venture Associates Opportunity II, LLC ("AVAO II LLC") is the general partner of AVAO II LP. The Reporting Person is a member of AVAO II LLC and disclaims beneficial ownership of such securities held by AVOF II, except to the extent of his pecuniary interest therein, if any.

SEC remarks

4. Reflects shares purchased in the Issuer's initial public offering.